chore(all): 0.10.0-alpha.1 release

Start implementing async transport

.clog.toml

@@ -0,0 +1,7 @@
+[clog]
+repository = "https://github.com/lettre/lettre"
+changelog = "CHANGELOG.md"
+
+[sections]
+Style = ["style"]
+Documentation = ["docs"]

.github/FUNDING.yml

@@ -0,0 +1 @@
+liberapay: amousset

.github/ISSUE_TEMPLATE/Bug_report.md

@@ -0,0 +1,21 @@
+---
+name: Bug report
+about: Create a report to help us improve
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Code allowing to reproduce the bug.
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Environment (please complete the following information):**
+- Lettre version
+- OS
+
+**Additional context**
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/Feature_request.md

@@ -0,0 +1,17 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

.github/workflows/audit.yml

@@ -0,0 +1,12 @@
+name: Security audit
+on:
+  schedule:
+    - cron: '0 0 * * *'
+jobs:
+  audit:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions-rs/audit-check@v1
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/test.yml

@@ -0,0 +1,115 @@
+name: Continuous integration
+
+on: [push, pull_request]
+
+jobs:
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - stable
+          - beta
+          - 1.40.0
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: ${{ matrix.rust }}
+          override: true
+      - run: sudo DEBIAN_FRONTEND=noninteractive apt-get -y install postfix
+      - run: smtp-sink 2525 1000&
+      - uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --no-default-features --features=native-tls,builder,r2d2,smtp-transport,file-transport,sendmail-transport
+      - run: rm target/debug/deps/liblettre-*
+      - uses: actions-rs/cargo@v1
+        with:
+          command: test
+      - run: rm target/debug/deps/liblettre-*
+      - uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --no-default-features --features=builder,smtp-transport,file-transport,sendmail-transport
+      - run: rm target/debug/deps/liblettre-*
+      - uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --features=async
+
+  check:
+    name: Check
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - stable
+          - beta
+          - 1.40.0
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: ${{ matrix.rust }}
+          override: true
+      - uses: actions-rs/cargo@v1
+        with:
+          command: check
+
+  fmt:
+    name: Rustfmt
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions-rs/cargo@v1
+        with:
+          command: fmt
+          args: --all -- --check
+
+  clippy:
+    name: Clippy
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - stable
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.rust }}
+          override: true
+      - uses: actions-rs/cargo@v1
+        with:
+          command: clippy
+          args: -- -D warnings
+
+#  coverage:
+#    name: Coverage
+#    runs-on: ubuntu-latest
+#    steps:
+#      - uses: actions/checkout@v1
+#      - uses: actions-rs/toolchain@v1
+#        with:
+#          toolchain: nightly
+#          override: true
+#      - run: sudo DEBIAN_FRONTEND=noninteractive apt-get -y install postfix
+#      - run: smtp-sink 2525 1000&
+#      - uses: actions-rs/cargo@v1
+#        with:
+#          command: test
+#          args: --no-fail-fast
+#        env:
+#          CARGO_INCREMENTAL: "0"
+#          RUSTFLAGS: "-Zprofile -Ccodegen-units=1 -Cinline-threshold=0 -Clink-dead-code -Coverflow-checks=off -Zno-landing-pads"
+#      - id: coverage
+#        uses: actions-rs/grcov@v0.1
+#      - name: Coveralls upload
+#        uses: coverallsapp/github-action@master
+#        with:
+#          github-token: ${{ secrets.GITHUB_TOKEN }}
+#          path-to-lcov: ${{ steps.coverage.outputs.report }}

.gitignore

@@ -1,2 +1,7 @@
-/target/
+.vscode/
+.project/
+.idea/
+lettre.sublime-*
+lettre.iml
+target/
 /Cargo.lock

.travis.yml

@@ -1,21 +0,0 @@
-language: rust
-sudo: required
-
-rust:
-  - stable
-  - beta
-  - nightly
-before_script:
-  - pip install 'travis-cargo<0.2' --user && export PATH=$HOME/.local/bin:$PATH
-script:
-  - |
-      travis-cargo build &&
-      travis-cargo test &&
-      travis-cargo doc
-after_success:
-  - travis-cargo --only stable doc-upload
-  - travis-cargo --only stable coveralls
-
-env:
-  global:
-    secure: "MaZ3TzuaAHuxmxQkfJdqRfkh7/ieScJRk0T/2yjysZhDMTYyRmp5wh/zkfW1ADuG0uc4Pqsxrsh1J9SVO7O0U5NJA8NKZi/pgiL+FHh0g4YtlHxy2xmFNB5am3Kyc+E7B4XylwTbA9S8ublVM0nvX7yX/a5fbwEUInVk2bA8fpc="

CHANGELOG.md

@@ -0,0 +1,210 @@
+<a name="v0.10.0-alpha.1"></a>
+### v0.10.0-alpha.1
+
+#### Upgrade notes
+
+Several breaking changes were made between 0.9 and 0.10, but changes should be straightforward:
+
+* The `lettre_email` crate has been merged into `lettre`. To migrate, replace `lettre_email` with `lettre::builder`
+  and make sure to enable the `builder` feature (it's enabled by default).
+* `SendableEmail` has been renamed to `Email` and `EmailBuilder::build()` produces it directly. To migrate,
+  rename `SendableEmail` to `Email`.
+* The `serde-impls` feature has been renamed to `serde`. To migrate, rename the feature.
+
+#### Features
+
+* Add `rustls` support ([29e4829](https://github.com/lettre/lettre/commit/29e4829), [39a0686](https://github.com/lettre/lettre/commit/39a0686))
+* Allow providing a custom message id ([50d96ad](https://github.com/lettre/lettre/commit/50d96ad))
+* Add `EmailAddress::is_valid` and `into_inner` ([e5a1248](https://github.com/lettre/lettre/commit/e5a1248))
+* Accept `Into<SendableEmail>` ([86e5181](https://github.com/lettre/lettre/commit/86e5181))
+* Allow forcing of a specific auth ([bf2adca](https://github.com/lettre/lettre/commit/bf2adca))
+* Add `build_body` ([e927d0b](https://github.com/lettre/lettre/commit/e927d0b))
+
+#### Changes
+
+* Move CI to Github Actions ([3eef024](https://github.com/lettre/lettre/commit/3eef024))
+* MSRV is now 1.36 ([d227cd4](https://github.com/lettre/lettre/commit/d227cd4))
+* Merged `lettre_email` into `lettre` ([0f3f27f](https://github.com/lettre/lettre/commit/0f3f27f))
+* Rename `serde-impls` feature to `serde` ([aac3e00](https://github.com/lettre/lettre/commit/aac3e00))
+* Use criterion for benchmarks ([eda7fc1](https://github.com/lettre/lettre/commit/eda7fc1))
+* Update to nom 5 ([5bc1cba](https://github.com/lettre/lettre/commit/5bc1cba))
+* Change website url schemes to https ([6014f5c](https://github.com/lettre/lettre/commit/6014f5c))
+* Use serde's `derive` feature instead of the `serde_derive` crate ([4fbe700](https://github.com/lettre/lettre/commit/4fbe700))
+* Merge `Email` and `SendableEmail` into `lettre::Email` ([ce37464](https://github.com/lettre/lettre/commit/ce37464))
+
+#### Bug Fixes
+
+* Timeout bug causing infinite hang ([6eff9d3](https://github.com/lettre/lettre/commit/6eff9d3))
+* Fix doc tests in website ([947af0a](https://github.com/lettre/lettre/commit/947af0a))
+* Fix docs for `domain` field ([0e05e0e](https://github.com/lettre/lettre/commit/0e05e0e))
+
+<a name="v0.9.2"></a>
+### v0.9.2 (2019-06-11)
+
+#### Bug Fixes
+
+* **email:**
+  * Fix compilation with Rust 1.36+ ([393ef8d](https://github.com/lettre/lettre/commit/393ef8dcd1b1c6a6119d0666d5f09b12f50f6b4b))
+
+<a name="v0.9.1"></a>
+### v0.9.1 (2019-05-05)
+
+#### Features
+
+* **email:**
+  * Re-export mime crate ([a0c8fb9](https://github.com/lettre/lettre/commit/a0c8fb9))
+
+<a name="v0.9.0"></a>
+### v0.9.0 (2019-03-17)
+
+#### Bug Fixes
+
+* **email:**
+  * Inserting 'from' from envelope into message headers ([058fa69](https://github.com/lettre/lettre/commit/058fa69))
+  * Do not include Bcc addresses in headers ([ee31bbe](https://github.com/lettre/lettre/commit/ee31bbe))
+
+* **transport:**
+  * Write timeout is not set in smtp transport ([d71b560](https://github.com/lettre/lettre/commit/d71b560))
+  * Client::read_response infinite loop ([72f3cd8](https://github.com/lettre/lettre/commit/72f3cd8))
+
+#### Features
+
+* **all:**
+  * Update dependencies
+  * Start using the failure crate for errors ([c10fe3d](https://github.com/lettre/lettre/commit/c10fe3d))
+
+* **transport:**
+  * Remove TLS 1.1 in accepted protocols by default (only allow TLS 1.2) ([4b48bdb](https://github.com/lettre/lettre/commit/4b48bdb))
+  * Initial support for XOAUTH2 ([ed7c164](https://github.com/lettre/lettre/commit/ed7c164))
+  * Remove support for CRAM-MD5 ([bc09aa2](https://github.com/lettre/lettre/commit/bc09aa2))
+  * SMTP connection pool implementation with r2d2 ([434654e](https://github.com/lettre/lettre/commit/434654e))
+  * Use md-5 and hmac instead of rust-crypto ([e7e0f34](https://github.com/lettre/lettre/commit/e7e0f34))
+  * Gmail transport simple example ([a8d8e2a](https://github.com/lettre/lettre/commit/a8d8e2a))
+
+* **email:**
+  * Add In-Reply-To and References headers ([fc91bb6](https://github.com/lettre/lettre/commit/fc91bb6))
+  * Remove non-chaining builder methods ([1baf8a9](https://github.com/lettre/lettre/commit/1baf8a9))
+
+<a name="v0.8.2"></a>
+### v0.8.2 (2018-05-03)
+
+
+#### Bug Fixes
+
+* **transport:**  Write timeout is not set in smtp transport ([cc3580a8](https://github.com/lettre/lettre/commit/cc3580a8942e11c2addf6677f05e16fb451c7ea0))
+
+#### Style
+
+* **all:**  Fix typos ([360c42ff](https://github.com/lettre/lettre/commit/360c42ffb8f706222eaad14e72619df1e4857814))
+
+#### Features
+
+* **all:**
+  *  Add set -xe option to build scripts ([57bbabaa](https://github.com/lettre/lettre/commit/57bbabaa6a10cc1a4de6f379e25babfee7adf6ad))
+  *  Move post-success scripts to separate files ([3177b58c](https://github.com/lettre/lettre/commit/3177b58c6d11ffae73c958713f6f0084173924e1))
+  *  Add website upload to travis build script ([a5294df6](https://github.com/lettre/lettre/commit/a5294df63728e14e24eeb851bb4403abd6a7bd36))
+  *  Add codecov upload in travis ([a03bfa00](https://github.com/lettre/lettre/commit/a03bfa008537b1d86ff789d0823e89ad5d99bd79))
+  *  Update README to put useful links at the top ([1ebbe660](https://github.com/lettre/lettre/commit/1ebbe660f5e142712f702c02d5d1e45211763b42))
+  *  Update badges in README and Cargo.toml ([f7ee5c42](https://github.com/lettre/lettre/commit/f7ee5c427ad71e4295f2f1d8e3e9e2dd850223e8))
+  *  Move docs from hugo to gitbook ([27935e32](https://github.com/lettre/lettre/commit/27935e32ef097db8db004569f35cad1d6cd30eca))
+* **transport:**  Use md-5 and hmac instead of rust-crypto ([0cf018a8](https://github.com/lettre/lettre/commit/0cf018a85e4ea1ad16c7216670da560cc915ec32))
+
+
+
+<a name="v0.8.1"></a>
+### v0.8.1 (2018-04-11)
+
+#### Fix
+
+* **all:**
+  *  Replace skeptic by some custom rustdoc invocations ([81bad131](https://github.com/lettre/lettre/commit/81bad1317519d330c46ea02f2b7a266b97cc00dd))
+
+#### Documentation
+
+* **all:**
+  *  Add changelog sections for style and docs ([b4d03ead](https://github.com/lettre/lettre/commit/b4d03ead8cce04e0c3d65a30e7a07acca9530f30))
+  *  Use clog to generate changelogs ([8981a775](https://github.com/lettre/lettre/commit/8981a7758c89be69974ef204c4390744aea94e4f), closes [#233](https://github.com/lettre/lettre/issues/233))
+
+#### Style
+
+* **transport-smtp:**  Avoid useless empty format strings ([f3271715](https://github.com/lettre/lettre/commit/f3271715ecaf2793c9064462184867e4f22b0ead))
+
+
+
+<a name="v0.8.0"></a>
+### v0.8.0 (2018-03-31)
+
+#### Added
+
+* Support binary files as attachment
+* Move doc to a dedicated website
+* Add tests for the doc using skeptic
+* Added a code of conduct
+* Use hostname as `ClientId` when available
+
+#### Changed
+
+* Detail in SMTP Response is now an enum
+* Use nom for parsing smtp responses
+* `Envelope` was moved from `lettre_email` to `lettre`
+* `EmailAddress::new()` now returns a `Result`
+* `SendableEmail` replaces `from` and `to` by `envelope` that returns an `Envelope`
+* `File` transport storage format has changed
+
+#### Fixed
+
+* Add missing "Bcc" headers when building the email
+* Specify utf-8 charset for html
+* Use parts for text and html methods to work with attachments
+
+#### Removed
+
+* `get_ehlo` and `reset` in SmtpTransport are now private
+
+<a name="v0.7.0"></a>
+### v0.7.0 (2017-10-08)
+
+#### Added
+
+* Allow validating server certificate
+* Initial (incomplete) attachments support
+
+#### Changed
+
+* Split into the *lettre* and *lettre_email* crates
+* A lot of small improvements
+* Use *tls-native* instead of *openssl* in smtp transport
+
+<a name="v0.6.2"></a>
+### v0.6.2 (2017-02-18)
+
+#### Changed
+
+* Update env-logger crate to 0.4
+* Update openssl crate to 0.9
+* Update uuid crate to 0.4
+
+<a name="v0.6.1"></a>
+### v0.6.1 (2016-10-19)
+
+#### Changes
+
+* **documentation**
+  * #91: Build separate docs for each release
+  * #96: Add complete documentation information to README
+
+#### Fixed
+
+* #85: Use address-list for "To", "From" etc.
+* #93: Force building tests before coverage computing
+
+<a name="v0.6.0"></a>
+### v0.6.0 (2016-05-05)
+
+#### Changes
+
+*  multipart support
+*  add non-consuming methods for Email builders
+* `add_header` does not return the builder anymore, 
+  for consistency with other methods. Use the `header`
+  method instead

CODE_OF_CONDUCT.md

@@ -0,0 +1,46 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as contributors and maintainers pledge to making participation in our project and our community a harassment-free experience for everyone, regardless of age, body size, disability, ethnicity, gender identity and expression, level of experience, nationality, personal appearance, race, religion, or sexual identity and orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable behavior and are expected to take appropriate and fair corrective action in response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, or to ban temporarily or permanently any contributor for other behaviors that they deem inappropriate, threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies both within project spaces and in public spaces when an individual is representing the project or its community. Examples of representing a project or community include using an official project e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event. Representation of a project may be further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be reported by contacting the project team at contact@lettre.at. The project team will review and investigate all complaints, and will respond in a way that it deems appropriate to the circumstances. The project team is obligated to maintain confidentiality with regard to the reporter of an incident. Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good faith may face temporary or permanent repercussions as determined by other members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4, available at [https://www.contributor-covenant.org/version/1/4][version]
+
+[homepage]: https://www.contributor-covenant.org
+[version]: https://www.contributor-covenant.org/version/1/4/

CONTRIBUTING.md

@@ -0,0 +1,43 @@
+## Contributing to Lettre
+
+The following guidelines are inspired from the [hyper project](https://github.com/hyperium/hyper/blob/master/CONTRIBUTING.md).
+
+### Code formatting
+
+All code must be formatted using `rustfmt`.
+
+### Commit Message Format
+
+Each commit message consists of a header, a body and a footer. The header has a special format that includes a type, a scope and a subject:
+
+```text
+<type>(<scope>): <subject> <BLANK LINE> <body> <BLANK LINE> <footer>
+```
+
+Any line of the commit message cannot be longer 72 characters.
+
+**type** must be one of the following:
+
+    feat: A new feature
+    fix: A bug fix
+    docs: Documentation only changes
+    style: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
+    perf: A code change that improves performance
+
+**scope** is the lettre part that is being touched. Examples:
+
+    email
+    transport-smtp
+    transport-file
+    transport
+    all
+
+The body explains the change, and the footer contains relevant changelog notes and references to fixed issues.
+
+### Release process
+
+Releases are made using `cargo-release`:
+
+```bash
+cargo release --dry-run 0.10.0 --prev-tag-name v0.9.2 -v
+```

COPYRIGHT

@@ -1,7 +0,0 @@
-Licensed under the Apache License, Version 2.0
-<LICENSE-APACHE or
-http://www.apache.org/licenses/LICENSE-2.0> or the MIT
-license <LICENSE-MIT or http://opensource.org/licenses/MIT>,
-at your option. All files in the project carrying such
-notice may not be copied, modified, or distributed except
-according to those terms.

Cargo.toml

@@ -1,29 +1,71 @@
 [package]
-
-name = "smtp"
-version = "0.0.13"
-description = "Simple SMTP client"
+name = "lettre"
+version = "0.10.0-alpha.1" # remember to update html_root_url
+description = "Email client"
 readme = "README.md"
-documentation = "http://amousset.github.io/rust-smtp/smtp/"
-repository = "https://github.com/amousset/rust-smtp"
-homepage = "https://github.com/amousset/rust-smtp"
-license = "MIT/Apache-2.0"
-authors = ["Alexis Mousset <contact@amousset.me>"]
-keywords = ["email", "smtp", "mailer"]
+homepage = "https://lettre.at"
+repository = "https://github.com/lettre/lettre"
+license = "MIT"
+authors = ["Alexis Mousset <contact@amousset.me>", "Kayo <kayo@illumium.org>"]
+categories = ["email", "network-programming"]
+keywords = ["email", "smtp", "mailer", "message", "sendmail"]
+edition = "2018"
+
+[badges]
+is-it-maintained-issue-resolution = { repository = "lettre/lettre" }
+is-it-maintained-open-issues = { repository = "lettre/lettre" }
+maintenance = { status = "actively-developed" }
 
 [dependencies]
-time = "0.1"
-uuid = "0.1"
-log = "0.3"
-rustc-serialize = "0.3"
-rust-crypto = "0.2"
-bufstream = "0.1"
-
-[dependencies.email]
-git = "https://github.com/amousset/rust-email.git"
+async-attributes = { version = "1.1", optional = true }
+async-std = { version = "1.5", optional = true, features = ["unstable"] }
+async-trait = { version = "0.1", optional = true }
+base64 = { version = "0.12", optional = true }
+bufstream = { version = "0.1", optional = true }
+hostname = { version = "0.3", optional = true }
+hyperx = { version = "1", optional = true, features = ["headers"] }
+idna = "0.2"
+line-wrap = "0.1"
+log = { version = "0.4", optional = true }
+mime = { version = "0.3", optional = true }
+native-tls = { version = "0.2", optional = true }
+nom = { version = "5", optional = true }
+once_cell = "1"
+quoted_printable = { version = "0.4", optional = true }
+r2d2 = { version = "0.8", optional = true }
+regex = "1"
+rustls = { version = "0.17", optional = true }
+serde = { version = "1", optional = true, features = ["derive"] }
+serde_json = { version = "1", optional = true }
+textnonce = { version = "0.7", optional = true }
+uuid = { version = "0.8", features = ["v4"] }
+webpki = { version = "0.21", optional = true }
+webpki-roots = { version = "0.19", optional = true }
 
 [dev-dependencies]
-env_logger = "*"
+criterion = "0.3"
+env_logger = "0.7"
+glob = "0.3"
+walkdir = "2"
+
+[[bench]]
+harness = false
+name = "transport_smtp"
 
 [features]
+async = ["async-std", "async-trait", "async-attributes"]
+builder = ["mime", "base64", "hyperx", "textnonce", "quoted_printable"]
+default = ["file-transport", "smtp-transport", "rustls-tls", "hostname", "r2d2", "sendmail-transport", "builder"]
+file-transport = ["serde", "serde_json"]
+rustls-tls = ["webpki", "webpki-roots", "rustls"]
+sendmail-transport = []
+smtp-transport = ["bufstream", "base64", "nom"]
 unstable = []
+
+[[example]]
+name = "smtp"
+required-features = ["smtp-transport"]
+
+[[example]]
+name = "smtp_gmail"
+required-features = ["smtp-transport", "native-tls"]

LICENSE

@@ -1,4 +1,5 @@
-Copyright (c) 2014 Alexis Mousset
+Copyright (c) 2014-2020 Alexis Mousset <contact@amousset.me>
+Copyright (c) 2018 K. <kayo@illumium.org>
 
 Permission is hereby granted, free of charge, to any
 person obtaining a copy of this software and associated

LICENSE-APACHE

@@ -1,201 +0,0 @@
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README.md

@@ -1,32 +1,104 @@
-rust-smtp [![Build Status](https://travis-ci.org/amousset/rust-smtp.svg?branch=master)](https://travis-ci.org/amousset/rust-smtp) [![Coverage Status](https://coveralls.io/repos/amousset/rust-smtp/badge.svg?branch=master)](https://coveralls.io/r/amousset/rust-smtp?branch=master) [![](https://meritbadge.herokuapp.com/smtp)](https://crates.io/crates/smtp)
-=========
+<h1 align="center">lettre</h1>
+<div align="center">
+ <strong>
+   A mailer library for Rust
+ </strong>
+</div>
 
-This library implements a simple SMTP client.
-See the [documentation](http://amousset.github.io/rust-smtp/smtp/) for more information.
+<br />
 
-Install
--------
+<div align="center">
+  <a href="https://docs.rs/lettre">
+    <img src="https://docs.rs/lettre/badge.svg"
+      alt="docs" />
+  </a>
+  <a href="https://crates.io/crates/lettre">
+    <img src="https://img.shields.io/crates/d/lettre.svg"
+      alt="downloads" />
+  </a>
+  <br />
+  <a href="https://gitter.im/lettre/lettre">
+    <img src="https://badges.gitter.im/lettre/lettre.svg"
+      alt="chat on gitter" />
+  </a>
+  <a href="https://lettre.at">
+    <img src="https://img.shields.io/badge/visit-website-blueviolet"
+      alt="website" />
+  </a>
+</div>
 
+---
+
+## Features
+
+Lettre provides the following features:
+
+* Multiple transport methods
+* Unicode support (for email content and addresses)
+* Secure delivery with SMTP using encryption and authentication
+* Easy email builders
+
+Lettre does not provide (for now):
+
+* Async support
+* Email parsing
+
+## Example
+
+This library requires Rust 1.20 or newer.
 To use this library, add the following to your `Cargo.toml`:
 
+
 ```toml
 [dependencies]
-smtp = "*"
+lettre = "0.9"
+lettre_email = "0.9"
 ```
 
-Tests
------
+```rust,no_run
+use lettre::{EmailTransport, SmtpTransport};
+use lettre_email::EmailBuilder;
+use std::path::Path;
 
-You can build and run the tests with `cargo test`.
+let email = EmailBuilder::new()
+    // Addresses can be specified by the tuple (email, alias)
+    .to(("user@example.org", "Firstname Lastname"))
+    // ... or by an address only
+    .from("user@example.com")
+    .subject("Hi, Hello world")
+    .text("Hello world.")
+    .build()
+    .unwrap();
 
-Documentation
--------------
+// Open a local connection on port 25
+let mut mailer = SmtpTransport::builder_unencrypted_localhost().unwrap()
+                                                                   .build();
+// Send the email
+let result = mailer.send(&email);
 
-You can build the documentation with `cargo doc`. It is also available on [GitHub pages](http://amousset.github.io/rust-smtp/smtp/).
+if result.is_ok() {
+    println!("Email sent");
+} else {
+    println!("Could not send email: {:?}", result);
+}
 
-License
--------
+assert!(result.is_ok());
+```
 
-This program is distributed under the terms of both the MIT license and the Apache License (Version 2.0).
+## Testing
 
-See LICENSE-APACHE, LICENSE-MIT, and COPYRIGHT for details.
+The `lettre` tests require an open mail server listening locally on port 2525 and the `sendmail` command.
+
+## Code of conduct
+
+Anyone who interacts with Lettre in any space, including but not limited to
+this GitHub repository, must follow our [code of conduct](https://github.com/lettre/lettre/blob/master/CODE_OF_CONDUCT.md).
+
+## License
+
+This program is distributed under the terms of the MIT license.
+
+The builder comes from [emailmessage-rs](https://github.com/katyo/emailmessage-rs) by
+Kayo, under MIT license.
+
+See [LICENSE](./LICENSE) for details.

benches/transport_smtp.rs

@@ -0,0 +1,40 @@
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+use lettre::{Message, SmtpTransport, Transport};
+
+fn bench_simple_send(c: &mut Criterion) {
+    let sender = SmtpTransport::builder("127.0.0.1").port(2525).build();
+
+    c.bench_function("send email", move |b| {
+        b.iter(|| {
+            let email = Message::builder()
+                .from("NoBody <nobody@domain.tld>".parse().unwrap())
+                .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+                .to("Hei <hei@domain.tld>".parse().unwrap())
+                .subject("Happy new year")
+                .body("Be happy!")
+                .unwrap();
+            let result = black_box(sender.send(&email));
+            assert!(result.is_ok());
+        })
+    });
+}
+
+fn bench_reuse_send(c: &mut Criterion) {
+    let sender = SmtpTransport::builder("127.0.0.1").port(2525).build();
+    c.bench_function("send email with connection reuse", move |b| {
+        b.iter(|| {
+            let email = Message::builder()
+                .from("NoBody <nobody@domain.tld>".parse().unwrap())
+                .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+                .to("Hei <hei@domain.tld>".parse().unwrap())
+                .subject("Happy new year")
+                .body("Be happy!")
+                .unwrap();
+            let result = black_box(sender.send(&email));
+            assert!(result.is_ok());
+        })
+    });
+}
+
+criterion_group!(benches, bench_simple_send, bench_reuse_send);
+criterion_main!(benches);

examples/client.rs

@@ -1,42 +0,0 @@
-// Copyright 2014 Alexis Mousset. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[macro_use]
-extern crate log;
-extern crate env_logger;
-extern crate smtp;
-
-use smtp::sender::{Sender, SenderBuilder};
-use smtp::mailer::EmailBuilder;
-
-fn main() {
-    env_logger::init().unwrap();
-
-    let mut email_builder = EmailBuilder::new();
-
-    email_builder = email_builder.to("user@localhost");
-    let email = email_builder.from("user@localhost")
-                         .body("Hello World!")
-                         .subject("Hello")
-                         .build();
-
-    let mut sender: Sender = SenderBuilder::localhost().hello_name("localhost")
-        .enable_connection_reuse(true).build();
-
-    for _ in (1..5) {
-        let _ = sender.send(email.clone());
-    }
-    let result = sender.send(email);
-    sender.close();
-
-    match result {
-        Ok(..) => info!("Email sent successfully"),
-        Err(error) => error!("{:?}", error),
-    }
-}

examples/smtp.rs

@@ -0,0 +1,25 @@
+use lettre::{Message, SmtpTransport, Transport};
+
+fn main() {
+    env_logger::init();
+    let email = Message::builder()
+        .from("NoBody <nobody@domain.tld>".parse().unwrap())
+        .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+        .to("Hei <hei@domain.tld>".parse().unwrap())
+        .subject("Happy new year")
+        .body("Be happy!")
+        .unwrap();
+
+    // Open a local connection on port 25
+    let mailer = SmtpTransport::unencrypted_localhost();
+    // Send the email
+    let result = mailer.send(&email);
+
+    if result.is_ok() {
+        println!("Email sent");
+    } else {
+        println!("Could not send email: {:?}", result);
+    }
+
+    assert!(result.is_ok());
+}

examples/smtp_gmail.rs

@@ -0,0 +1,33 @@
+use lettre::{transport::smtp::authentication::Credentials, Message, SmtpTransport, Transport};
+
+fn main() {
+    let email = Message::builder()
+        .from("NoBody <nobody@domain.tld>".parse().unwrap())
+        .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+        .to("Hei <hei@domain.tld>".parse().unwrap())
+        .subject("Happy new year")
+        .body("Be happy!")
+        .unwrap();
+
+    let creds = Credentials::new(
+        "example_username".to_string(),
+        "example_password".to_string(),
+    );
+
+    // Open a remote connection to gmail
+    let mailer = SmtpTransport::relay("smtp.gmail.com")
+        .unwrap()
+        .credentials(creds)
+        .build();
+
+    // Send the email
+    let result = mailer.send(&email);
+
+    if result.is_ok() {
+        println!("Email sent");
+    } else {
+        println!("Could not send email: {:?}", result);
+    }
+
+    assert!(result.is_ok());
+}

src/address.rs

@@ -0,0 +1,280 @@
+//! Representation of an email address
+
+use idna::domain_to_ascii;
+use once_cell::sync::Lazy;
+use regex::Regex;
+use std::{
+    convert::{TryFrom, TryInto},
+    error::Error,
+    ffi::OsStr,
+    fmt::{Display, Formatter, Result as FmtResult},
+    net::IpAddr,
+    str::FromStr,
+};
+
+/// Email address
+///
+/// This type contains email in canonical form (_user@domain.tld_).
+///
+/// **NOTE**: Enable feature "serde" to be able serialize/deserialize it using [serde](https://serde.rs/).
+#[derive(Debug, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]
+pub struct Address {
+    /// User part
+    pub user: String,
+    /// Domain part
+    pub domain: String,
+    /// Complete address
+    complete: String,
+}
+
+impl<U, D> TryFrom<(U, D)> for Address
+where
+    U: Into<String>,
+    D: Into<String>,
+{
+    type Error = AddressError;
+
+    fn try_from(from: (U, D)) -> Result<Self, Self::Error> {
+        let (user, domain) = from;
+        let user = user.into();
+        Address::check_user(&user)?;
+        let domain = domain.into();
+        Address::check_domain(&domain)?;
+        let complete = format!("{}@{}", &user, &domain);
+        Ok(Address {
+            user,
+            domain,
+            complete,
+        })
+    }
+}
+
+// Regex from the specs
+// https://html.spec.whatwg.org/multipage/forms.html#valid-e-mail-address
+// It will mark esoteric email addresses like quoted string as invalid
+static USER_RE: Lazy<Regex> =
+    Lazy::new(|| Regex::new(r"^(?i)[a-z0-9.!#$%&'*+/=?^_`{|}~-]+\z").unwrap());
+static DOMAIN_RE: Lazy<Regex> = Lazy::new(|| {
+    Regex::new(
+        r"(?i)^[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?(?:.[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?)*$",
+    )
+    .unwrap()
+});
+// literal form, ipv4 or ipv6 address (SMTP 4.1.3)
+static LITERAL_RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"(?i)\[([A-f0-9:\.]+)\]\z").unwrap());
+
+impl Address {
+    /// Create email address from parts
+    pub fn new<U: Into<String>, D: Into<String>>(user: U, domain: D) -> Result<Self, AddressError> {
+        (user, domain).try_into()
+    }
+
+    fn check_user(user: &str) -> Result<(), AddressError> {
+        if USER_RE.is_match(user) {
+            Ok(())
+        } else {
+            Err(AddressError::InvalidUser)
+        }
+    }
+
+    fn check_domain(domain: &str) -> Result<(), AddressError> {
+        Address::check_domain_ascii(domain).or_else(|_| {
+            domain_to_ascii(domain)
+                .map_err(|_| AddressError::InvalidDomain)
+                .and_then(|domain| Address::check_domain_ascii(&domain))
+        })
+    }
+
+    fn check_domain_ascii(domain: &str) -> Result<(), AddressError> {
+        if DOMAIN_RE.is_match(domain) {
+            return Ok(());
+        }
+
+        if let Some(caps) = LITERAL_RE.captures(domain) {
+            if let Some(cap) = caps.get(1) {
+                if cap.as_str().parse::<IpAddr>().is_ok() {
+                    return Ok(());
+                }
+            }
+        }
+
+        Err(AddressError::InvalidDomain)
+    }
+}
+
+impl Display for Address {
+    fn fmt(&self, f: &mut Formatter) -> FmtResult {
+        f.write_str(&self.complete)
+    }
+}
+
+impl FromStr for Address {
+    type Err = AddressError;
+
+    fn from_str(val: &str) -> Result<Self, AddressError> {
+        if val.is_empty() || !val.contains('@') {
+            return Err(AddressError::MissingParts);
+        }
+
+        let parts: Vec<&str> = val.rsplitn(2, '@').collect();
+        let user = parts[1];
+        let domain = parts[0];
+
+        Address::check_user(user)
+            .and_then(|_| Address::check_domain(domain))
+            .map(|_| Address {
+                user: user.into(),
+                domain: domain.into(),
+                complete: val.to_string(),
+            })
+    }
+}
+
+impl AsRef<str> for Address {
+    fn as_ref(&self) -> &str {
+        &self.complete.as_ref()
+    }
+}
+
+impl AsRef<OsStr> for Address {
+    fn as_ref(&self) -> &OsStr {
+        self.complete.as_ref()
+    }
+}
+
+#[derive(Debug, PartialEq, Clone, Copy)]
+pub enum AddressError {
+    MissingParts,
+    Unbalanced,
+    InvalidUser,
+    InvalidDomain,
+    InvalidUtf8b,
+}
+
+impl Error for AddressError {}
+
+impl Display for AddressError {
+    fn fmt(&self, f: &mut Formatter) -> FmtResult {
+        match self {
+            AddressError::MissingParts => f.write_str("Missing domain or user"),
+            AddressError::Unbalanced => f.write_str("Unbalanced angle bracket"),
+            AddressError::InvalidUser => f.write_str("Invalid email user"),
+            AddressError::InvalidDomain => f.write_str("Invalid email domain"),
+            AddressError::InvalidUtf8b => f.write_str("Invalid UTF8b data"),
+        }
+    }
+}
+
+#[cfg(feature = "serde")]
+pub mod serde {
+    use crate::address::Address;
+    use serde::{
+        de::{Deserializer, Error as DeError, MapAccess, Visitor},
+        ser::Serializer,
+        Deserialize, Serialize,
+    };
+    use std::fmt::{Formatter, Result as FmtResult};
+
+    impl Serialize for Address {
+        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+        where
+            S: Serializer,
+        {
+            serializer.serialize_str(&self.to_string())
+        }
+    }
+
+    impl<'de> Deserialize<'de> for Address {
+        fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+        where
+            D: Deserializer<'de>,
+        {
+            enum Field {
+                User,
+                Domain,
+            };
+
+            const FIELDS: &[&str] = &["user", "domain"];
+
+            impl<'de> Deserialize<'de> for Field {
+                fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+                where
+                    D: Deserializer<'de>,
+                {
+                    struct FieldVisitor;
+
+                    impl<'de> Visitor<'de> for FieldVisitor {
+                        type Value = Field;
+
+                        fn expecting(&self, formatter: &mut Formatter) -> FmtResult {
+                            formatter.write_str("'user' or 'domain'")
+                        }
+
+                        fn visit_str<E>(self, value: &str) -> Result<Field, E>
+                        where
+                            E: DeError,
+                        {
+                            match value {
+                                "user" => Ok(Field::User),
+                                "domain" => Ok(Field::Domain),
+                                _ => Err(DeError::unknown_field(value, FIELDS)),
+                            }
+                        }
+                    }
+
+                    deserializer.deserialize_identifier(FieldVisitor)
+                }
+            }
+
+            struct AddressVisitor;
+
+            impl<'de> Visitor<'de> for AddressVisitor {
+                type Value = Address;
+
+                fn expecting(&self, formatter: &mut Formatter) -> FmtResult {
+                    formatter.write_str("email address string or object")
+                }
+
+                fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
+                where
+                    E: DeError,
+                {
+                    s.parse().map_err(DeError::custom)
+                }
+
+                fn visit_map<V>(self, mut map: V) -> Result<Self::Value, V::Error>
+                where
+                    V: MapAccess<'de>,
+                {
+                    let mut user = None;
+                    let mut domain = None;
+                    while let Some(key) = map.next_key()? {
+                        match key {
+                            Field::User => {
+                                if user.is_some() {
+                                    return Err(DeError::duplicate_field("user"));
+                                }
+                                let val = map.next_value()?;
+                                Address::check_user(val).map_err(DeError::custom)?;
+                                user = Some(val);
+                            }
+                            Field::Domain => {
+                                if domain.is_some() {
+                                    return Err(DeError::duplicate_field("domain"));
+                                }
+                                let val = map.next_value()?;
+                                Address::check_domain(val).map_err(DeError::custom)?;
+                                domain = Some(val);
+                            }
+                        }
+                    }
+                    let user: &str = user.ok_or_else(|| DeError::missing_field("user"))?;
+                    let domain: &str = domain.ok_or_else(|| DeError::missing_field("domain"))?;
+                    Ok(Address::new(user, domain).unwrap())
+                }
+            }
+
+            deserializer.deserialize_any(AddressVisitor)
+        }
+    }
+}

src/client/authentication.rs

@@ -1,51 +0,0 @@
-// Copyright 2014 Alexis Mousset. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! Provides authentication functions
-
-use serialize::base64::{self, ToBase64, FromBase64};
-use serialize::hex::ToHex;
-use crypto::hmac::Hmac;
-use crypto::md5::Md5;
-use crypto::mac::Mac;
-
-use NUL;
-
-/// Returns a PLAIN mecanism response
-pub fn plain(username: &str, password: &str) -> String {
-    format!("{}{}{}{}", NUL, username, NUL, password).as_bytes().to_base64(base64::STANDARD)
-}
-
-/// Returns a CRAM-MD5 mecanism response
-pub fn cram_md5(username: &str, password: &str, encoded_challenge: &str) -> String {
-    // TODO manage errors
-    let challenge = encoded_challenge.from_base64().unwrap();
-
-    let mut hmac = Hmac::new(Md5::new(), password.as_bytes());
-    hmac.input(&challenge);
-
-    format!("{} {}", username, hmac.result().code().to_hex()).as_bytes().to_base64(base64::STANDARD)
-}
-
-#[cfg(test)]
-mod test {
-    use super::{plain, cram_md5};
-
-    #[test]
-    fn test_plain() {
-        assert_eq!(plain("username", "password"), "AHVzZXJuYW1lAHBhc3N3b3Jk");
-    }
-
-    #[test]
-    fn test_cram_md5() {
-        assert_eq!(cram_md5("alice", "wonderland",
-            "PDE3ODkzLjEzMjA2NzkxMjNAdGVzc2VyYWN0LnN1c2FtLmluPg=="),
-            "YWxpY2UgNjRiMmE0M2MxZjZlZDY4MDZhOTgwOTE0ZTIzZTc1ZjA=");
-    }
-}

src/client/mod.rs

@@ -1,254 +0,0 @@
-// Copyright 2014 Alexis Mousset. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! SMTP client
-
-use std::string::String;
-use std::net::{SocketAddr, ToSocketAddrs};
-use std::io::{BufRead, Read, Write};
-
-use bufstream::BufStream;
-
-use response::{Response, Severity, Category};
-use error::SmtpResult;
-use client::net::{Connector, SmtpStream};
-use client::authentication::{plain, cram_md5};
-use {CRLF, MESSAGE_ENDING};
-
-pub mod net;
-mod authentication;
-
-/// Returns the string after adding a dot at the beginning of each line starting with a dot
-///
-/// Reference : https://tools.ietf.org/html/rfc5321#page-62 (4.5.2. Transparency)
-#[inline]
-fn escape_dot(string: &str) -> String {
-    if string.starts_with(".") {
-        format!(".{}", string)
-    } else {
-        string.to_string()
-    }.replace("\r.", "\r..")
-     .replace("\n.", "\n..")
-}
-
-/// Returns the string replacing all the CRLF with "\<CRLF\>"
-#[inline]
-fn escape_crlf(string: &str) -> String {
-    string.replace(CRLF, "<CR><LF>")
-}
-
-/// Structure that implements the SMTP client
-pub struct Client<S: Write + Read = SmtpStream> {
-    /// TCP stream between client and server
-    /// Value is None before connection
-    stream: Option<BufStream<S>>,
-    /// Socket we are connecting to
-    server_addr: SocketAddr,
-
-}
-
-macro_rules! return_err (
-    ($err: expr, $client: ident) => ({
-        return Err(From::from($err))
-    })
-);
-
-impl<S: Write + Read = SmtpStream> Client<S> {
-    /// Creates a new SMTP client
-    ///
-    /// It does not connects to the server, but only creates the `Client`
-    pub fn new<A: ToSocketAddrs>(addr: A) -> Client<S> {
-        Client{
-            stream: None,
-            server_addr: addr.to_socket_addrs().ok().expect("could not parse server address").next().unwrap(),
-        }
-    }
-}
-
-impl<S: Connector + Write + Read = SmtpStream> Client<S> {
-    /// Closes the SMTP transaction if possible
-    pub fn close(&mut self) {
-        let _ = self.quit();
-        self.stream = None;
-    }
-
-    /// Connects to the configured server
-    pub fn connect(&mut self) -> SmtpResult {
-        // Connect should not be called when the client is already connected
-        if self.stream.is_some() {
-            return_err!("The connection is already established", self);
-        }
-
-        // Try to connect
-        self.stream = Some(BufStream::new(try!(Connector::connect(&self.server_addr))));
-
-        self.get_reply()
-    }
-
-    /// Checks if the server is connected using the NOOP SMTP command
-    pub fn is_connected(&mut self) -> bool {
-        self.noop().is_ok()
-    }
-
-    /// Sends an SMTP command
-    pub fn command(&mut self, command: &str) -> SmtpResult {
-        self.send_server(command, CRLF)
-    }
-
-    /// Send a HELO command and fills `server_info`
-    pub fn helo(&mut self, hostname: &str) -> SmtpResult {
-        self.command(&format!("HELO {}", hostname))
-    }
-
-    /// Sends a EHLO command and fills `server_info`
-    pub fn ehlo(&mut self, hostname: &str) -> SmtpResult {
-        self.command(&format!("EHLO {}", hostname))
-    }
-
-    /// Sends a MAIL command
-    pub fn mail(&mut self, address: &str, options: Option<&str>) -> SmtpResult {
-        match options {
-            Some(ref options) => self.command(&format!("MAIL FROM:<{}> {}", address, options)),
-            None => self.command(&format!("MAIL FROM:<{}>", address)),
-        }
-    }
-
-    /// Sends a RCPT command
-    pub fn rcpt(&mut self, address: &str) -> SmtpResult {
-        self.command(&format!("RCPT TO:<{}>", address))
-    }
-
-    /// Sends a DATA command
-    pub fn data(&mut self) -> SmtpResult {
-        self.command("DATA")
-    }
-
-    /// Sends a QUIT command
-    pub fn quit(&mut self) -> SmtpResult {
-        self.command("QUIT")
-    }
-
-    /// Sends a NOOP command
-    pub fn noop(&mut self) -> SmtpResult {
-        self.command("NOOP")
-    }
-
-    /// Sends a HELP command
-    pub fn help(&mut self, argument: Option<&str>) -> SmtpResult {
-        match argument {
-            Some(ref argument) => self.command(&format!("HELP {}", argument)),
-            None => self.command("HELP"),
-        }
-    }
-
-    /// Sends a VRFY command
-    pub fn vrfy(&mut self, address: &str) -> SmtpResult {
-        self.command(&format!("VRFY {}", address))
-    }
-
-    /// Sends a EXPN command
-    pub fn expn(&mut self, address: &str) -> SmtpResult {
-        self.command(&format!("EXPN {}", address))
-    }
-
-    /// Sends a RSET command
-    pub fn rset(&mut self) -> SmtpResult {
-        self.command("RSET")
-    }
-
-    /// Sends an AUTH command with PLAIN mecanism
-    pub fn auth_plain(&mut self, username: &str, password: &str) -> SmtpResult {
-        self.command(&format!("AUTH PLAIN {}", plain(username, password)))
-    }
-
-    /// Sends an AUTH command with CRAM-MD5 mecanism
-    pub fn auth_cram_md5(&mut self, username: &str, password: &str) -> SmtpResult {
-        let encoded_challenge = try!(self.command("AUTH CRAM-MD5")).first_word().expect("No challenge");
-        self.command(&format!("AUTH CRAM-MD5 {}", cram_md5(username, password, &encoded_challenge)))
-    }
-
-    /// Sends the message content
-    pub fn message(&mut self, message_content: &str) -> SmtpResult {
-        self.send_server(&escape_dot(message_content), MESSAGE_ENDING)
-    }
-
-    /// Sends a string to the server and gets the response
-    fn send_server(&mut self, string: &str, end: &str) -> SmtpResult {
-        if self.stream.is_none() {
-            return Err(From::from("Connection closed"));
-        }
-
-        try!(write!(self.stream.as_mut().unwrap(), "{}{}", string, end));
-        try!(self.stream.as_mut().unwrap().flush());
-
-        debug!("Wrote: {}", escape_crlf(string));
-
-        self.get_reply()
-    }
-
-    /// Gets the SMTP response
-    fn get_reply(&mut self) -> SmtpResult {
-        let mut line = String::new();
-        try!(self.stream.as_mut().unwrap().read_line(&mut line));
-
-        // If the string is too short to be a response code
-        if line.len() < 3 {
-            return Err(From::from("Could not parse reply code, line too short"));
-        }
-
-        let (severity, category, detail) =  match (line[0..1].parse::<Severity>(), line[1..2].parse::<Category>(), line[2..3].parse::<u8>()) {
-            (Ok(severity), Ok(category), Ok(detail)) => (severity, category, detail),
-            _ => return Err(From::from("Could not parse reply code")),
-        };
-
-        let mut message = Vec::new();
-
-        // 3 chars for code + space + CRLF
-        while line.len() > 6 {
-            let end = line.len() - 2;
-            message.push(line[4..end].to_string());
-            if line.as_bytes()[3] == '-' as u8 {
-                line.clear();
-                try!(self.stream.as_mut().unwrap().read_line(&mut line));
-            } else {
-                line.clear();
-            }
-        }
-
-        let response = Response::new(severity, category, detail, message);
-
-        match response.is_positive() {
-            true => Ok(response),
-            false => Err(From::from(response)),
-        }
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::{escape_dot, escape_crlf};
-
-    #[test]
-    fn test_escape_dot() {
-        assert_eq!(escape_dot(".test"), "..test");
-        assert_eq!(escape_dot("\r.\n.\r\n"), "\r..\n..\r\n");
-        assert_eq!(escape_dot("test\r\n.test\r\n"), "test\r\n..test\r\n");
-        assert_eq!(escape_dot("test\r\n.\r\ntest"), "test\r\n..\r\ntest");
-    }
-
-    #[test]
-    fn test_escape_crlf() {
-        assert_eq!(escape_crlf("\r\n"), "<CR><LF>");
-        assert_eq!(escape_crlf("EHLO my_name\r\n"), "EHLO my_name<CR><LF>");
-        assert_eq!(
-            escape_crlf("EHLO my_name\r\nSIZE 42\r\n"),
-            "EHLO my_name<CR><LF>SIZE 42<CR><LF>"
-        );
-    }
-}

src/client/net.rs

@@ -1,30 +0,0 @@
-// Copyright 2014 Alexis Mousset. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! A trait to represent a stream
-
-use std::io;
-use std::net::SocketAddr;
-use std::net::TcpStream;
-
-/// A trait for the concept of opening a stream
-pub trait Connector {
-    /// Opens a connection to the given IP socket
-    fn connect(addr: &SocketAddr) -> io::Result<Self>;
-}
-
-impl Connector for SmtpStream {
-    fn connect(addr: &SocketAddr) -> io::Result<SmtpStream> {
-        TcpStream::connect(addr)
-    }
-}
-
-/// Represents an atual SMTP network stream
-//Used later for ssl
-pub type SmtpStream = TcpStream;

src/error.rs

@@ -1,89 +1,52 @@
-// Copyright 2014 Alexis Mousset. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
+use std::{
+    error::Error as StdError,
+    fmt::{self, Display, Formatter},
+};
 
-//! Error and result type for SMTP clients
-
-use std::error::Error;
-use std::io;
-use std::fmt::{Display, Formatter};
-use std::fmt;
-
-use response::{Severity, Response};
-use self::SmtpError::*;
-
-/// An enum of all error kinds.
+// FIXME message-specific errors
+/// Error type for email content
 #[derive(Debug)]
-pub enum SmtpError {
-    /// Transient error, 4xx reply code
-    ///
-    /// [RFC 5321, section 4.2.1](https://tools.ietf.org/html/rfc5321#section-4.2.1)
-    TransientError(Response),
-    /// Permanent error, 5xx reply code
-    ///
-    /// [RFC 5321, section 4.2.1](https://tools.ietf.org/html/rfc5321#section-4.2.1)
-    PermanentError(Response),
-    /// TODO
-    ClientError(String),
+pub enum Error {
+    /// Missing from in envelope
+    MissingFrom,
+    /// Missing to in envelope
+    MissingTo,
+    /// Can only be one from in envelope
+    TooManyFrom,
+    /// Invalid email: missing at
+    EmailMissingAt,
+    /// Invalid email: missing local part
+    EmailMissingLocalPart,
+    /// Invalid email: missing domain
+    EmailMissingDomain,
+    /// Cannot parse filename for attachment
+    CannotParseFilename,
     /// IO error
-    IoError(io::Error),
+    Io(std::io::Error),
+    /// Non-ASCII chars
+    NonAsciiChars,
 }
 
-impl Display for SmtpError {
-    fn fmt(&self, fmt: &mut Formatter) -> Result<(), fmt::Error> {
-        fmt.write_str(self.description())
+impl Display for Error {
+    fn fmt(&self, fmt: &mut Formatter<'_>) -> Result<(), fmt::Error> {
+        fmt.write_str(&match self {
+            Error::MissingFrom => "missing source address, invalid envelope".to_string(),
+            Error::MissingTo => "missing destination address, invalid envelope".to_string(),
+            Error::TooManyFrom => "there can only be one source address".to_string(),
+            Error::EmailMissingAt => "missing @ in email address".to_string(),
+            Error::EmailMissingLocalPart => "missing local part in email address".to_string(),
+            Error::EmailMissingDomain => "missing domain in email address".to_string(),
+            Error::CannotParseFilename => "could not parse attachment filename".to_string(),
+            Error::NonAsciiChars => "contains non-ASCII chars".to_string(),
+            Error::Io(e) => e.to_string(),
+        })
     }
 }
 
-impl Error for SmtpError {
-    fn description(&self) -> &str {
-        match *self {
-            TransientError(_) => "a transient error occured during the SMTP transaction",
-            PermanentError(_) => "a permanent error occured during the SMTP transaction",
-            ClientError(_) => "an unknown error occured",
-            IoError(_) => "an I/O error occured",
-        }
-    }
-
-    fn cause(&self) -> Option<&Error> {
-        match *self {
-            IoError(ref err) => Some(&*err as &Error),
-            _ => None,
-        }
+impl From<std::io::Error> for Error {
+    fn from(err: std::io::Error) -> Error {
+        Error::Io(err)
     }
 }
 
-impl From<io::Error> for SmtpError {
-    fn from(err: io::Error) -> SmtpError {
-        IoError(err)
-    }
-}
-
-impl From<Response> for SmtpError {
-    fn from(response: Response) -> SmtpError {
-        match response.severity() {
-            Severity::TransientNegativeCompletion => TransientError(response),
-            Severity::PermanentNegativeCompletion => PermanentError(response),
-            _ => ClientError("Unknown error code".to_string())
-        }
-    }
-}
-
-impl From<&'static str> for SmtpError {
-    fn from(string: &'static str) -> SmtpError {
-        ClientError(string.to_string())
-    }
-}
-
-/// SMTP result type
-pub type SmtpResult = Result<Response, SmtpError>;
-
-#[cfg(test)]
-mod test {
-    // TODO
-}
+impl StdError for Error {}

src/extension.rs

@@ -1,110 +0,0 @@
-// Copyright 2014 Alexis Mousset. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! ESMTP features
-
-use std::str::FromStr;
-use std::result::Result;
-
-use response::Response;
-use self::Extension::*;
-
-/// Supported ESMTP keywords
-#[derive(PartialEq,Eq,Copy,Clone,Debug)]
-pub enum Extension {
-    /// 8BITMIME keyword
-    ///
-    /// RFC 6152: https://tools.ietf.org/html/rfc6152
-    EightBitMime,
-    /// SMTPUTF8 keyword
-    ///
-    /// RFC 6531: https://tools.ietf.org/html/rfc6531
-    SmtpUtfEight,
-    /// STARTTLS keyword
-    ///
-    /// RFC 2487: https://tools.ietf.org/html/rfc2487
-    StartTls,
-    /// AUTH PLAIN mecanism
-    ///
-    /// RFC 4616: https://tools.ietf.org/html/rfc4616
-    PlainAuthentication,
-    /// AUTH CRAM-MD5 mecanism
-    ///
-    /// RFC 2195: https://tools.ietf.org/html/rfc2195
-    CramMd5Authentication,
-}
-
-impl Extension {
-    fn from_str(s: &str) -> Result<Vec<Extension>, &'static str> {
-        let splitted : Vec<&str> = s.split(' ').collect();
-        match (splitted[0], splitted.len()) {
-            ("8BITMIME", 1) => Ok(vec![EightBitMime]),
-            ("SMTPUTF8", 1) => Ok(vec![SmtpUtfEight]),
-            ("STARTTLS", 1) => Ok(vec![StartTls]),
-            ("AUTH", _) => {
-                let mut mecanisms: Vec<Extension> = vec![];
-                for &mecanism in &splitted[1..] {
-                    match mecanism {
-                        "PLAIN" => mecanisms.push(PlainAuthentication),
-                        "CRAM-MD5" => mecanisms.push(CramMd5Authentication),
-                        _ => (),
-                    }
-                }
-                Ok(mecanisms)
-            },
-            _ => Err("Unknown extension"),
-        }
-    }
-
-    /// Parses supported ESMTP features
-    pub fn parse_esmtp_response(response: &Response) -> Vec<Extension> {
-        let mut esmtp_features: Vec<Extension> = Vec::new();
-
-        for line in response.message() {
-            if let Ok(keywords) = Extension::from_str(&line) {
-                for keyword in keywords {
-                    esmtp_features.push(keyword);
-                }
-            };
-        }
-
-        esmtp_features
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::Extension;
-    use response::{Severity, Category, Response};
-
-    #[test]
-    fn test_from_str() {
-        assert_eq!(Extension::from_str("8BITMIME"), Ok(vec![Extension::EightBitMime]));
-        assert_eq!(Extension::from_str("AUTH PLAIN"), Ok(vec![Extension::PlainAuthentication]));
-        assert_eq!(Extension::from_str("AUTH PLAIN LOGIN CRAM-MD5"), Ok(vec![Extension::PlainAuthentication, Extension::CramMd5Authentication]));
-        assert_eq!(Extension::from_str("AUTH CRAM-MD5 PLAIN"), Ok(vec![Extension::CramMd5Authentication, Extension::PlainAuthentication]));
-        assert_eq!(Extension::from_str("AUTH DIGEST-MD5 PLAIN CRAM-MD5"), Ok(vec![Extension::PlainAuthentication, Extension::CramMd5Authentication]));
-    }
-
-    #[test]
-    fn test_parse_esmtp_response() {
-        assert_eq!(Extension::parse_esmtp_response(&Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "2".parse::<Category>().unwrap(),
-            1,
-            vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]
-        )), vec![Extension::EightBitMime]);
-        assert_eq!(Extension::parse_esmtp_response(&Response::new(
-            "4".parse::<Severity>().unwrap(),
-            "3".parse::<Category>().unwrap(),
-            3,
-            vec!["me".to_string(), "8BITMIME".to_string(), "AUTH PLAIN CRAM-MD5".to_string()]
-        )), vec![Extension::EightBitMime, Extension::PlainAuthentication, Extension::CramMd5Authentication]);
-    }
-}

src/lib.rs

@@ -1,186 +1,240 @@
-// Copyright 2014 Alexis Mousset. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
+//! Lettre is an email library that allows creating and sending messages. It provides:
+//!
+//! * An easy to use email builder
+//! * Pluggable email transports
+//! * Unicode support
+//! * Secure defaults
+//!
+//! Lettre requires Rust 1.40 or newer.
+//!
+//! ## Optional features
+//!
+//! * **builder**: Message builder
+//! * **file-transport**: Transport that write messages into a file
+//! * **smtp-transport**: Transport over SMTP
+//! * **sendmail-transport**: Transport over SMTP
+//! * **rustls-tls**: TLS support with the `rustls` crate
+//! * **native-tls**: TLS support with the `native-tls` crate
+//! * **r2d2**: Connection pool for SMTP transport
+//! * **log**: Logging using the `log` crate
+//! * **serde**: Serialization/Deserialization of entities
+//! * **hostname**: Ability to try to use actual hostname in SMTP transaction
 
-//! # Rust SMTP client
-//!
-//! This client should tend to follow [RFC 5321](https://tools.ietf.org/html/rfc5321), but is still
-//! a work in progress. It is designed to efficiently send emails from a rust application to a
-//! relay email server.
-//!
-//! It implements the following extensions:
-//!
-//! * 8BITMIME ([RFC 6152](https://tools.ietf.org/html/rfc6152))
-//! * AUTH ([RFC 4954](http://tools.ietf.org/html/rfc4954))
-//!
-//! It will eventually implement the following extensions:
-//!
-//! * STARTTLS ([RFC 2487](http://tools.ietf.org/html/rfc2487))
-//! * SMTPUTF8 ([RFC 6531](http://tools.ietf.org/html/rfc6531))
-//!
-//! ## Architecture
-//!
-//! This client is divided into three parts:
-//!
-//! * client: a low level SMTP client providing all SMTP commands
-//! * sender: a high level SMTP client providing an easy method to send emails
-//! * mailer: generates the email to be sent with the sender
-//!
-//! ## Usage
-//!
-//! ### Simple example
-//!
-//! This is the most basic example of usage:
-//!
-//! ```rust,no_run
-//! use smtp::sender::{Sender, SenderBuilder};
-//! use smtp::mailer::EmailBuilder;
-//!
-//! // Create an email
-//! let email = EmailBuilder::new()
-//!     // Addresses can be specified by the couple (email, alias)
-//!     .to(("user@example.org", "Firstname Lastname"))
-//!     // ... or by an address only
-//!     .from("user@example.com")
-//!     .subject("Hi, Hello world")
-//!     .body("Hello world.")
-//!     .build();
-//!
-//! // Open a local connection on port 25
-//! let mut sender = SenderBuilder::localhost().build();
-//! // Send the email
-//! let result = sender.send(email);
-//!
-//! assert!(result.is_ok());
-//! ```
-//!
-//! ### Complete example
-//!
-//! ```rust,no_run
-//! use smtp::sender::{Sender, SenderBuilder};
-//! use smtp::mailer::EmailBuilder;
-//!
-//! let mut builder = EmailBuilder::new();
-//! builder = builder.to(("user@example.org", "Alias name"));
-//! builder = builder.cc(("user@example.net", "Alias name"));
-//! builder = builder.from("no-reply@example.com");
-//! builder = builder.from("no-reply@example.eu");
-//! builder = builder.sender("no-reply@example.com");
-//! builder = builder.subject("Hello world");
-//! builder = builder.body("Hi, Hello world.");
-//! builder = builder.reply_to("contact@example.com");
-//! builder = builder.add_header(("X-Custom-Header", "my header"));
-//!
-//! let email = builder.build();
-//!
-//! // Connect to a remote server on a custom port
-//! let mut sender = SenderBuilder::new(("server.tld", 10025))
-//!     // Set the name sent during EHLO/HELO, default is `localhost`
-//!     .hello_name("my.hostname.tld")
-//!     // Add credentials for authentication
-//!     .credentials("username", "password")
-//!     // Enable connection reuse
-//!     .enable_connection_reuse(true).build();
-//!
-//! let result_1 = sender.send(email.clone());
-//! assert!(result_1.is_ok());
-//!
-//! // The second email will use the same connection
-//! let result_2 = sender.send(email);
-//! assert!(result_2.is_ok());
-//!
-//! // Explicitely close the SMTP transaction as we enabled connection reuse
-//! sender.close();
-//! ```
-//!
-//! ### Using the client directly
-//!
-//! If you just want to send an email without using `Email` to provide headers:
-//!
-//! ```rust,no_run
-//! use smtp::sender::{Sender, SenderBuilder};
-//! use smtp::sendable_email::SimpleSendableEmail;
-//!
-//! // Create a minimal email
-//! let email = SimpleSendableEmail::new(
-//!     "test@example.com",
-//!     "test@example.org",
-//!     "Hello world !"
-//! );
-//!
-//! let mut sender = SenderBuilder::localhost().build();
-//! let result = sender.send(email);
-//! assert!(result.is_ok());
-//! ```
-//!
-//! ### Lower level
-//!
-//! You can also send commands, here is a simple email transaction without error handling:
-//!
-//! ```rust,no_run
-//! use smtp::client::Client;
-//! use smtp::client::net::SmtpStream;
-//! use smtp::SMTP_PORT;
-//! use std::net::TcpStream;
-//!
-//! let mut email_client: Client<SmtpStream> = Client::new(("localhost", SMTP_PORT));
-//! let _ = email_client.connect();
-//! let _ = email_client.ehlo("my_hostname");
-//! let _ = email_client.mail("user@example.com", None);
-//! let _ = email_client.rcpt("user@example.org");
-//! let _ = email_client.data();
-//! let _ = email_client.message("Test email");
-//! let _ = email_client.quit();
-//! ```
+#![doc(html_root_url = "https://docs.rs/lettre/0.10.0")]
+#![doc(html_favicon_url = "https://lettre.at/favicon.png")]
+#![doc(html_logo_url = "https://avatars0.githubusercontent.com/u/15113230?v=4")]
+#![deny(
+    missing_copy_implementations,
+    trivial_casts,
+    trivial_numeric_casts,
+    unstable_features,
+    unused_import_braces,
+    unsafe_code
+)]
 
-#![deny(missing_docs)]
-
-#[macro_use] extern crate log;
-extern crate rustc_serialize as serialize;
-extern crate crypto;
-extern crate time;
-extern crate uuid;
-extern crate email;
-extern crate bufstream;
-
-mod extension;
-pub mod client;
-pub mod sender;
-pub mod response;
+pub mod address;
 pub mod error;
-pub mod sendable_email;
-pub mod mailer;
+#[cfg(feature = "builder")]
+pub mod message;
+pub mod transport;
 
-// Registrated port numbers:
-// https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml
+use crate::error::Error;
+#[cfg(feature = "builder")]
+pub use crate::message::{
+    header::{self, Headers},
+    EmailFormat, Mailbox, Mailboxes, Message,
+};
+#[cfg(feature = "file-transport")]
+pub use crate::transport::file::FileTransport;
+#[cfg(feature = "sendmail-transport")]
+pub use crate::transport::sendmail::SendmailTransport;
+#[cfg(feature = "smtp-transport")]
+pub use crate::transport::smtp::client::net::TlsParameters;
+#[cfg(all(feature = "smtp-transport", feature = "connection-pool"))]
+pub use crate::transport::smtp::r2d2::SmtpConnectionManager;
+#[cfg(feature = "smtp-transport")]
+pub use crate::transport::smtp::{SmtpTransport, Tls};
+pub use crate::{address::Address, transport::stub::StubTransport};
+#[cfg(feature = "builder")]
+use std::convert::TryFrom;
+use std::{error::Error as StdError, fmt};
 
-/// Default smtp port
-pub static SMTP_PORT: u16 = 25;
+/// Simple email envelope representation
+///
+/// We only accept mailboxes, and do not support source routes (as per RFC).
+#[derive(PartialEq, Eq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Envelope {
+    /// The envelope recipients' addresses
+    ///
+    /// This can not be empty.
+    forward_path: Vec<Address>,
+    /// The envelope sender address
+    reverse_path: Option<Address>,
+}
 
-/// Default smtps port
-pub static SMTPS_PORT: u16 = 465;
+impl Envelope {
+    /// Creates a new envelope, which may fail if `to` is empty.
+    pub fn new(from: Option<Address>, to: Vec<Address>) -> Result<Envelope, Error> {
+        if to.is_empty() {
+            return Err(Error::MissingTo);
+        }
+        Ok(Envelope {
+            forward_path: to,
+            reverse_path: from,
+        })
+    }
 
-/// Default submission port
-pub static SUBMISSION_PORT: u16 = 587;
+    /// Destination addresses of the envelope
+    pub fn to(&self) -> &[Address] {
+        self.forward_path.as_slice()
+    }
 
-// Useful strings and characters
+    /// Source address of the envelope
+    pub fn from(&self) -> Option<&Address> {
+        self.reverse_path.as_ref()
+    }
+}
 
-/// The word separator for SMTP transactions
-pub static SP: &'static str = " ";
+impl TryFrom<&Headers> for Envelope {
+    type Error = Error;
 
-/// The line ending for SMTP transactions (carriage return + line feed)
-pub static CRLF: &'static str = "\r\n";
+    fn try_from(headers: &Headers) -> Result<Self, Self::Error> {
+        let from = match headers.get::<header::Sender>() {
+            // If there is a Sender, use it
+            Some(header::Sender(a)) => Some(a.email.clone()),
+            // ... else try From
+            None => match headers.get::<header::From>() {
+                Some(header::From(a)) => {
+                    let from: Vec<Mailbox> = a.clone().into();
+                    if from.len() > 1 {
+                        return Err(Error::TooManyFrom);
+                    }
+                    Some(from[0].email.clone())
+                }
+                None => None,
+            },
+        };
 
-/// Colon
-pub static COLON: &'static str = ":";
+        fn add_addresses_from_mailboxes(
+            addresses: &mut Vec<Address>,
+            mailboxes: Option<&Mailboxes>,
+        ) {
+            if let Some(mailboxes) = mailboxes {
+                for mailbox in mailboxes.iter() {
+                    addresses.push(mailbox.email.clone());
+                }
+            }
+        }
+        let mut to = vec![];
+        add_addresses_from_mailboxes(&mut to, headers.get::<header::To>().map(|h| &h.0));
+        add_addresses_from_mailboxes(&mut to, headers.get::<header::Cc>().map(|h| &h.0));
+        add_addresses_from_mailboxes(&mut to, headers.get::<header::Bcc>().map(|h| &h.0));
 
-/// The ending of message content
-pub static MESSAGE_ENDING: &'static str = "\r\n.\r\n";
+        Self::new(from, to)
+    }
+}
 
-/// NUL unicode character
-pub static NUL: &'static str = "\0";
+/// Transport method for emails
+pub trait Transport {
+    /// Result types for the transport
+    type Ok: fmt::Debug;
+    type Error: StdError;
+
+    /// Sends the email
+    #[cfg(feature = "builder")]
+    fn send(&self, message: &Message) -> Result<Self::Ok, Self::Error> {
+        let raw = message.formatted();
+        self.send_raw(message.envelope(), &raw)
+    }
+
+    fn send_raw(&self, envelope: &Envelope, email: &[u8]) -> Result<Self::Ok, Self::Error>;
+}
+
+#[cfg(feature = "async")]
+pub mod r#async {
+
+    use super::*;
+    use async_trait::async_trait;
+
+    #[async_trait]
+    pub trait Transport {
+        /// Result types for the transport
+        type Ok: fmt::Debug;
+        type Error: StdError;
+
+        /// Sends the email
+        #[cfg(feature = "builder")]
+        // TODO take &Message
+        async fn send(&self, message: Message) -> Result<Self::Ok, Self::Error> {
+            let raw = message.formatted();
+            let envelope = message.envelope();
+            self.send_raw(&envelope, &raw).await
+        }
+
+        async fn send_raw(
+            &self,
+            envelope: &Envelope,
+            email: &[u8],
+        ) -> Result<Self::Ok, Self::Error>;
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::message::{header, Mailbox, Mailboxes};
+    use hyperx::header::Headers;
+
+    #[test]
+    fn envelope_from_headers() {
+        let from = Mailboxes::new().with("kayo@example.com".parse().unwrap());
+        let to = Mailboxes::new().with("amousset@example.com".parse().unwrap());
+
+        let mut headers = Headers::new();
+        headers.set(header::From(from));
+        headers.set(header::To(to));
+
+        assert_eq!(
+            Envelope::try_from(&headers).unwrap(),
+            Envelope::new(
+                Some(Address::new("kayo", "example.com").unwrap()),
+                vec![Address::new("amousset", "example.com").unwrap()]
+            )
+            .unwrap()
+        );
+    }
+
+    #[test]
+    fn envelope_from_headers_sender() {
+        let from = Mailboxes::new().with("kayo@example.com".parse().unwrap());
+        let sender = Mailbox::new(None, "kayo2@example.com".parse().unwrap());
+        let to = Mailboxes::new().with("amousset@example.com".parse().unwrap());
+
+        let mut headers = Headers::new();
+        headers.set(header::From(from));
+        headers.set(header::Sender(sender));
+        headers.set(header::To(to));
+
+        assert_eq!(
+            Envelope::try_from(&headers).unwrap(),
+            Envelope::new(
+                Some(Address::new("kayo2", "example.com").unwrap()),
+                vec![Address::new("amousset", "example.com").unwrap()]
+            )
+            .unwrap()
+        );
+    }
+
+    #[test]
+    fn envelope_from_headers_no_to() {
+        let from = Mailboxes::new().with("kayo@example.com".parse().unwrap());
+        let sender = Mailbox::new(None, "kayo2@example.com".parse().unwrap());
+
+        let mut headers = Headers::new();
+        headers.set(header::From(from));
+        headers.set(header::Sender(sender));
+
+        assert!(Envelope::try_from(&headers).is_err(),);
+    }
+}

src/mailer/mod.rs

@@ -1,212 +0,0 @@
-// Copyright 2014 Alexis Mousset. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! Simple email (very incomplete)
-
-use email::{MimeMessage, Header, Address};
-use time::{now, Tm};
-use uuid::Uuid;
-
-use sendable_email::SendableEmail;
-
-/// Converts an adress or an address with an alias to an `Address`
-pub trait ToHeader {
-    /// Converts to an `Address` struct
-    fn to_header(&self) -> Header;
-}
-
-impl ToHeader for Header {
-    fn to_header(&self) -> Header {
-        (*self).clone()
-    }
-}
-
-impl<'a> ToHeader for (&'a str, &'a str) {
-    fn to_header(&self) -> Header {
-        let (name, value) = *self;
-        Header::new(name.to_string(), value.to_string())
-    }
-}
-
-/// Converts an adress or an address with an alias to an `Address`
-pub trait ToAddress {
-    /// Converts to an `Address` struct
-    fn to_address(&self) -> Address;
-}
-
-impl ToAddress for Address {
-    fn to_address(&self) -> Address {
-        (*self).clone()
-    }
-}
-
-impl<'a> ToAddress for &'a str {
-    fn to_address(&self) -> Address {
-        Address::new_mailbox(self.to_string())
-    }
-}
-
-impl<'a> ToAddress for (&'a str, &'a str) {
-    fn to_address(&self) -> Address {
-        let (address, alias) = *self;
-        Address::new_mailbox_with_name(address.to_string(), alias.to_string())
-    }
-}
-
-/// TODO
-#[derive(PartialEq,Eq,Clone,Debug)]
-pub struct EmailBuilder {
-    /// Email content
-    content: Email,
-    /// Date issued
-    date_issued: bool,
-}
-
-/// Simple email representation
-#[derive(PartialEq,Eq,Clone,Debug)]
-pub struct Email {
-    /// Message
-    message: MimeMessage,
-    /// The enveloppe recipients addresses
-    to: Vec<String>,
-    /// The enveloppe sender address
-    from: Option<String>,
-    /// Message-ID
-    message_id: Uuid,
-}
-
-impl Email {
-    /// Displays the formatted email content
-    pub fn as_string(&self) -> String {
-        self.message.as_string()
-    }
-}
-
-impl EmailBuilder {
-    /// Creates a new empty email
-    pub fn new() -> EmailBuilder {
-        let current_message = Uuid::new_v4();
-
-        let mut email = Email {
-            message: MimeMessage::new_blank_message(),
-            to: vec![],
-            from: None,
-            message_id: current_message,
-        };
-
-        email.message.headers.insert(
-            Header::new_with_value("Message-ID".to_string(),
-                format!("<{}@rust-smtp>", current_message)
-            ).unwrap()
-        );
-
-        EmailBuilder {
-            content: email,
-            date_issued: false,
-        }
-    }
-
-    /// Sets the email body
-    pub fn body(mut self, body: &str) -> EmailBuilder {
-        self.content.message.body = body.to_string();
-        self
-    }
-
-    /// Add a generic header
-    pub fn add_header<A: ToHeader>(mut self, header: A) -> EmailBuilder {
-        self.insert_header(header);
-        self
-    }
-
-    fn insert_header<A: ToHeader>(&mut self, header: A) {
-        self.content.message.headers.insert(header.to_header());
-    }
-
-    /// Adds a `From` header and store the sender address
-    pub fn from<A: ToAddress>(mut self, address: A) -> EmailBuilder {
-        self.content.from = Some(address.to_address().get_address().unwrap());
-        self.insert_header(("From", address.to_address().to_string().as_ref()));
-        self
-    }
-
-    /// Adds a `To` header and store the recipient address
-    pub fn to<A: ToAddress>(mut self, address: A) -> EmailBuilder {
-        self.content.to.push(address.to_address().get_address().unwrap());
-        self.insert_header(("To", address.to_address().to_string().as_ref()));
-        self
-    }
-
-    /// Adds a `Cc` header and store the recipient address
-    pub fn cc<A: ToAddress>(mut self, address: A) -> EmailBuilder {
-        self.content.to.push(address.to_address().get_address().unwrap());
-        self.insert_header(("Cc", address.to_address().to_string().as_ref()));
-        self
-    }
-
-    /// Adds a `Reply-To` header
-    pub fn reply_to<A: ToAddress>(mut self, address: A) -> EmailBuilder {
-        self.insert_header(("Reply-To", address.to_address().to_string().as_ref()));
-        self
-    }
-
-    /// Adds a `Sender` header
-    pub fn sender<A: ToAddress>(mut self, address: A) -> EmailBuilder {
-        self.content.from = Some(address.to_address().get_address().unwrap());
-        self.insert_header(("Sender", address.to_address().to_string().as_ref()));
-        self
-    }
-
-    /// Adds a `Subject` header
-    pub fn subject(mut self, subject: &str) -> EmailBuilder {
-        self.insert_header(("Subject", subject));
-        self
-    }
-
-    /// Adds a `Date` header with the given date
-    pub fn date(mut self, date: &Tm) -> EmailBuilder {
-        self.insert_header(("Date", Tm::rfc822(date).to_string().as_ref()));
-        self.date_issued = true;
-        self
-    }
-
-    /// Build the Email
-    pub fn build(mut self) -> Email {
-        if !self.date_issued {
-            self.insert_header(("Date", Tm::rfc822(&now()).to_string().as_ref()));
-        }
-        self.content.message.update_headers();
-        self.content
-    }
-}
-
-impl SendableEmail for Email {
-    /// Return the to addresses, and fails if it is not set
-    fn to_addresses(&self) -> Vec<String> {
-        if self.to.is_empty() {
-            panic!("The To field is empty")
-        }
-        self.to.clone()
-    }
-
-    /// Return the from address, and fails if it is not set
-    fn from_address(&self) -> String {
-        match self.from {
-            Some(ref from_address) => from_address.clone(),
-            None => panic!("The From field is empty"),
-        }
-    }
-
-    fn message(&self) -> String {
-        format! ("{}", self.as_string())
-    }
-
-    fn message_id(&self) -> String {
-        format!("{}", self.message_id)
-    }
-}

src/message/encoder.rs

@@ -0,0 +1,251 @@
+use crate::message::header::ContentTransferEncoding;
+use line_wrap::{crlf, line_wrap, LineEnding};
+use std::io::Write;
+
+/// Encoder trait
+pub trait EncoderCodec: Send {
+    /// Encode all data
+    fn encode(&mut self, input: &[u8]) -> Vec<u8>;
+}
+
+/// 7bit codec
+///
+/// WARNING: Panics when passed non-ascii chars
+struct SevenBitCodec {
+    line_wrapper: EightBitCodec,
+}
+
+impl SevenBitCodec {
+    pub fn new() -> Self {
+        SevenBitCodec {
+            line_wrapper: EightBitCodec::new(),
+        }
+    }
+}
+
+impl EncoderCodec for SevenBitCodec {
+    fn encode(&mut self, input: &[u8]) -> Vec<u8> {
+        if input.iter().all(u8::is_ascii) {
+            self.line_wrapper.encode(input)
+        } else {
+            panic!("")
+        }
+    }
+}
+
+/// Quoted-Printable codec
+///
+struct QuotedPrintableCodec();
+
+impl QuotedPrintableCodec {
+    pub fn new() -> Self {
+        QuotedPrintableCodec()
+    }
+}
+
+impl EncoderCodec for QuotedPrintableCodec {
+    fn encode(&mut self, input: &[u8]) -> Vec<u8> {
+        quoted_printable::encode(input)
+    }
+}
+
+/// Base64 codec
+///
+struct Base64Codec {
+    line_wrapper: EightBitCodec,
+}
+
+impl Base64Codec {
+    pub fn new() -> Self {
+        Base64Codec {
+            // TODO probably 78, 76 is for qp
+            line_wrapper: EightBitCodec::new().with_limit(78 - 2),
+        }
+    }
+}
+
+impl EncoderCodec for Base64Codec {
+    fn encode(&mut self, input: &[u8]) -> Vec<u8> {
+        self.line_wrapper.encode(base64::encode(input).as_bytes())
+    }
+}
+
+/// 8bit codec
+///
+struct EightBitCodec {
+    max_length: usize,
+}
+
+const DEFAULT_MAX_LINE_LENGTH: usize = 1000 - 2;
+
+impl EightBitCodec {
+    pub fn new() -> Self {
+        EightBitCodec {
+            max_length: DEFAULT_MAX_LINE_LENGTH,
+        }
+    }
+
+    pub fn with_limit(mut self, max_length: usize) -> Self {
+        self.max_length = max_length;
+        self
+    }
+}
+
+impl EncoderCodec for EightBitCodec {
+    fn encode(&mut self, input: &[u8]) -> Vec<u8> {
+        let ending = &crlf();
+
+        let mut out = vec![0_u8; input.len() + input.len() / self.max_length * ending.len()];
+        let mut writer: &mut [u8] = out.as_mut();
+        writer.write_all(input).unwrap();
+
+        line_wrap(&mut out, input.len(), self.max_length, ending);
+        out
+    }
+}
+
+/// Binary codec
+///
+struct BinaryCodec;
+
+impl BinaryCodec {
+    pub fn new() -> Self {
+        BinaryCodec
+    }
+}
+
+impl EncoderCodec for BinaryCodec {
+    fn encode(&mut self, input: &[u8]) -> Vec<u8> {
+        input.into()
+    }
+}
+
+pub fn codec(encoding: Option<&ContentTransferEncoding>) -> Box<dyn EncoderCodec> {
+    use self::ContentTransferEncoding::*;
+    if let Some(encoding) = encoding {
+        match encoding {
+            SevenBit => Box::new(SevenBitCodec::new()),
+            QuotedPrintable => Box::new(QuotedPrintableCodec::new()),
+            Base64 => Box::new(Base64Codec::new()),
+            EightBit => Box::new(EightBitCodec::new()),
+            Binary => Box::new(BinaryCodec::new()),
+        }
+    } else {
+        Box::new(BinaryCodec::new())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn seven_bit_encode() {
+        let mut c = SevenBitCodec::new();
+
+        assert_eq!(
+            &String::from_utf8(c.encode("Hello, world!".as_bytes())).unwrap(),
+            "Hello, world!"
+        );
+    }
+
+    #[test]
+    #[should_panic]
+    fn seven_bit_encode_panic() {
+        let mut c = SevenBitCodec::new();
+        c.encode("Hello, мир!".as_bytes());
+    }
+
+    #[test]
+    fn quoted_printable_encode() {
+        let mut c = QuotedPrintableCodec::new();
+
+        assert_eq!(
+            &String::from_utf8(c.encode("Привет, мир!".as_bytes())).unwrap(),
+            "=D0=9F=D1=80=D0=B8=D0=B2=D0=B5=D1=82, =D0=BC=D0=B8=D1=80!"
+        );
+
+        assert_eq!(&String::from_utf8(c.encode("Текст письма в уникоде".as_bytes())).unwrap(),
+                   "=D0=A2=D0=B5=D0=BA=D1=81=D1=82 =D0=BF=D0=B8=D1=81=D1=8C=D0=BC=D0=B0 =D0=B2 =\r\n=D1=83=D0=BD=D0=B8=D0=BA=D0=BE=D0=B4=D0=B5");
+    }
+
+    #[test]
+    fn base64_encode() {
+        let mut c = Base64Codec::new();
+
+        assert_eq!(
+            &String::from_utf8(c.encode("Привет, мир!".as_bytes())).unwrap(),
+            "0J/RgNC40LLQtdGCLCDQvNC40YAh"
+        );
+
+        assert_eq!(
+            &String::from_utf8(c.encode("Текст письма в уникоде подлиннее.".as_bytes())).unwrap(),
+            concat!(
+                "0KLQtdC60YHRgiDQv9C40YHRjNC80LAg0LIg0YPQvdC40LrQ",
+                "vtC00LUg0L/QvtC00LvQuNC90L3Q\r\ntdC1Lg=="
+            )
+        );
+
+        assert_eq!(
+            &String::from_utf8(c.encode(
+                "Ну прямо супер-длинный текст письма в уникоде, который уж точно ну никак не поместиться в 78 байт, как ни крути, я гарантирую.".as_bytes()
+                    )).unwrap(),
+
+                concat!("0J3RgyDQv9GA0Y/QvNC+INGB0YPQv9C10YAt0LTQu9C40L3QvdGL0Lkg0YLQtdC60YHRgiDQv9C4\r\n",
+                        "0YHRjNC80LAg0LIg0YPQvdC40LrQvtC00LUsINC60L7RgtC+0YDRi9C5INGD0LYg0YLQvtGH0L3Q\r\n",
+                        "viDQvdGDINC90LjQutCw0Log0L3QtSDQv9C+0LzQtdGB0YLQuNGC0YzRgdGPINCyIDc4INCx0LDQ\r\n",
+                        "udGCLCDQutCw0Log0L3QuCDQutGA0YPRgtC4LCDRjyDQs9Cw0YDQsNC90YLQuNGA0YPRji4=")
+        );
+        assert_eq!(
+            &String::from_utf8(c.encode(
+                "Ну прямо супер-длинный текст письма в уникоде, который уж точно ну никак не поместиться в 78 байт, как ни крути, я гарантирую это.".as_bytes()
+            )).unwrap(),
+
+                concat!("0J3RgyDQv9GA0Y/QvNC+INGB0YPQv9C10YAt0LTQu9C40L3QvdGL0Lkg0YLQtdC60YHRgiDQv9C4\r\n",
+                        "0YHRjNC80LAg0LIg0YPQvdC40LrQvtC00LUsINC60L7RgtC+0YDRi9C5INGD0LYg0YLQvtGH0L3Q\r\n",
+                        "viDQvdGDINC90LjQutCw0Log0L3QtSDQv9C+0LzQtdGB0YLQuNGC0YzRgdGPINCyIDc4INCx0LDQ\r\n",
+                        "udGCLCDQutCw0Log0L3QuCDQutGA0YPRgtC4LCDRjyDQs9Cw0YDQsNC90YLQuNGA0YPRjiDRjdGC\r\n",
+                        "0L4u")
+        );
+    }
+
+    #[test]
+    fn base64_encodeed() {
+        let mut c = Base64Codec::new();
+
+        assert_eq!(
+            &String::from_utf8(c.encode("Chunk.".as_bytes())).unwrap(),
+            "Q2h1bmsu"
+        );
+    }
+
+    #[test]
+    fn eight_bit_encode() {
+        let mut c = EightBitCodec::new();
+
+        assert_eq!(
+            &String::from_utf8(c.encode("Hello, world!".as_bytes())).unwrap(),
+            "Hello, world!"
+        );
+
+        assert_eq!(
+            &String::from_utf8(c.encode("Hello, мир!".as_bytes())).unwrap(),
+            "Hello, мир!"
+        );
+    }
+
+    #[test]
+    fn binary_encode() {
+        let mut c = BinaryCodec::new();
+
+        assert_eq!(
+            &String::from_utf8(c.encode("Hello, world!".as_bytes())).unwrap(),
+            "Hello, world!"
+        );
+
+        assert_eq!(
+            &String::from_utf8(c.encode("Hello, мир!".as_bytes())).unwrap(),
+            "Hello, мир!"
+        );
+    }
+}

src/message/header/content.rs

@@ -0,0 +1,121 @@
+use hyperx::{
+    header::{Formatter as HeaderFormatter, Header, RawLike},
+    Error as HeaderError, Result as HyperResult,
+};
+use std::{
+    fmt::{Display, Formatter as FmtFormatter, Result as FmtResult},
+    str::{from_utf8, FromStr},
+};
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum ContentTransferEncoding {
+    SevenBit,
+    QuotedPrintable,
+    Base64,
+    // 8BITMIME
+    EightBit,
+    Binary,
+}
+
+impl Default for ContentTransferEncoding {
+    fn default() -> Self {
+        ContentTransferEncoding::SevenBit
+    }
+}
+
+impl Display for ContentTransferEncoding {
+    fn fmt(&self, f: &mut FmtFormatter) -> FmtResult {
+        use self::ContentTransferEncoding::*;
+        f.write_str(match *self {
+            SevenBit => "7bit",
+            QuotedPrintable => "quoted-printable",
+            Base64 => "base64",
+            EightBit => "8bit",
+            Binary => "binary",
+        })
+    }
+}
+
+impl FromStr for ContentTransferEncoding {
+    type Err = String;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        use self::ContentTransferEncoding::*;
+        match s {
+            "7bit" => Ok(SevenBit),
+            "quoted-printable" => Ok(QuotedPrintable),
+            "base64" => Ok(Base64),
+            "8bit" => Ok(EightBit),
+            "binary" => Ok(Binary),
+            _ => Err(s.into()),
+        }
+    }
+}
+
+impl Header for ContentTransferEncoding {
+    fn header_name() -> &'static str {
+        "Content-Transfer-Encoding"
+    }
+
+    // FIXME HeaderError->HeaderError, same for result
+    fn parse_header<'a, T>(raw: &'a T) -> HyperResult<Self>
+    where
+        T: RawLike<'a>,
+        Self: Sized,
+    {
+        raw.one()
+            .ok_or(HeaderError::Header)
+            .and_then(|r| from_utf8(r).map_err(|_| HeaderError::Header))
+            .and_then(|s| {
+                s.parse::<ContentTransferEncoding>()
+                    .map_err(|_| HeaderError::Header)
+            })
+    }
+
+    fn fmt_header(&self, f: &mut HeaderFormatter) -> FmtResult {
+        f.fmt_line(&format!("{}", self))
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::ContentTransferEncoding;
+    use hyperx::header::Headers;
+
+    #[test]
+    fn format_content_transfer_encoding() {
+        let mut headers = Headers::new();
+
+        headers.set(ContentTransferEncoding::SevenBit);
+
+        assert_eq!(
+            format!("{}", headers),
+            "Content-Transfer-Encoding: 7bit\r\n"
+        );
+
+        headers.set(ContentTransferEncoding::Base64);
+
+        assert_eq!(
+            format!("{}", headers),
+            "Content-Transfer-Encoding: base64\r\n"
+        );
+    }
+
+    #[test]
+    fn parse_content_transfer_encoding() {
+        let mut headers = Headers::new();
+
+        headers.set_raw("Content-Transfer-Encoding", "7bit");
+
+        assert_eq!(
+            headers.get::<ContentTransferEncoding>(),
+            Some(&ContentTransferEncoding::SevenBit)
+        );
+
+        headers.set_raw("Content-Transfer-Encoding", "base64");
+
+        assert_eq!(
+            headers.get::<ContentTransferEncoding>(),
+            Some(&ContentTransferEncoding::Base64)
+        );
+    }
+}

src/message/header/mailbox.rs

@@ -0,0 +1,289 @@
+use crate::message::{
+    mailbox::{Mailbox, Mailboxes},
+    utf8_b,
+};
+use hyperx::{
+    header::{Formatter as HeaderFormatter, Header, RawLike},
+    Error as HeaderError, Result as HyperResult,
+};
+use std::{fmt::Result as FmtResult, slice::Iter, str::from_utf8};
+
+/// Header which can contains multiple mailboxes
+pub trait MailboxesHeader {
+    fn join_mailboxes(&mut self, other: Self);
+}
+
+macro_rules! mailbox_header {
+    ($(#[$doc:meta])*($type_name: ident, $header_name: expr)) => {
+        $(#[$doc])*
+        #[derive(Debug, Clone, PartialEq)]
+        pub struct $type_name(pub Mailbox);
+
+        impl Header for $type_name {
+            fn header_name() -> &'static str {
+                $header_name
+            }
+
+            fn parse_header<'a, T>(raw: &'a T) -> HyperResult<Self> where
+    T: RawLike<'a>,
+    Self: Sized {
+                raw.one()
+                    .ok_or(HeaderError::Header)
+                    .and_then(parse_mailboxes)
+                    .and_then(|mbs| {
+                        mbs.into_single().ok_or(HeaderError::Header)
+                    }).map($type_name)
+            }
+
+            fn fmt_header(&self, f: &mut HeaderFormatter) -> FmtResult {
+                f.fmt_line(&self.0.recode_name(utf8_b::encode))
+            }
+        }
+    };
+}
+
+macro_rules! mailboxes_header {
+    ($(#[$doc:meta])*($type_name: ident, $header_name: expr)) => {
+        $(#[$doc])*
+        #[derive(Debug, Clone, PartialEq)]
+        pub struct $type_name(pub Mailboxes);
+
+        impl MailboxesHeader for $type_name {
+            fn join_mailboxes(&mut self, other: Self) {
+                self.0.extend(other.0);
+            }
+        }
+
+        impl Header for $type_name {
+            fn header_name() -> &'static str {
+                $header_name
+            }
+
+            fn parse_header<'a, T>(raw: &'a T) -> HyperResult<$type_name>
+            where
+                T: RawLike<'a>,
+                Self: Sized,
+            {
+                raw.one()
+                    .ok_or(HeaderError::Header)
+                    .and_then(parse_mailboxes)
+                    .map($type_name)
+            }
+
+            fn fmt_header(&self, f: &mut HeaderFormatter) -> FmtResult {
+                format_mailboxes(self.0.iter(), f)
+            }
+        }
+    };
+}
+
+mailbox_header! {
+    /**
+
+    `Sender` header
+
+    This header contains [`Mailbox`](::Mailbox) associated with sender.
+
+    ```no_test
+    header::Sender("Mr. Sender <sender@example.com>".parse().unwrap())
+    ```
+     */
+    (Sender, "Sender")
+}
+
+mailboxes_header! {
+    /**
+
+    `From` header
+
+    This header contains [`Mailboxes`](::Mailboxes).
+
+     */
+    (From, "From")
+}
+
+mailboxes_header! {
+    /**
+
+    `Reply-To` header
+
+    This header contains [`Mailboxes`](::Mailboxes).
+
+     */
+    (ReplyTo, "Reply-To")
+}
+
+mailboxes_header! {
+    /**
+
+    `To` header
+
+    This header contains [`Mailboxes`](::Mailboxes).
+
+     */
+    (To, "To")
+}
+
+mailboxes_header! {
+    /**
+
+    `Cc` header
+
+    This header contains [`Mailboxes`](::Mailboxes).
+
+     */
+    (Cc, "Cc")
+}
+
+mailboxes_header! {
+    /**
+
+    `Bcc` header
+
+    This header contains [`Mailboxes`](::Mailboxes).
+
+     */
+    (Bcc, "Bcc")
+}
+
+fn parse_mailboxes(raw: &[u8]) -> HyperResult<Mailboxes> {
+    if let Ok(src) = from_utf8(raw) {
+        if let Ok(mbs) = src.parse() {
+            return Ok(mbs);
+        }
+    }
+    Err(HeaderError::Header)
+}
+
+fn format_mailboxes<'a>(mbs: Iter<'a, Mailbox>, f: &mut HeaderFormatter) -> FmtResult {
+    f.fmt_line(&Mailboxes::from(
+        mbs.map(|mb| mb.recode_name(utf8_b::encode))
+            .collect::<Vec<_>>(),
+    ))
+}
+
+#[cfg(test)]
+mod test {
+    use super::{From, Mailbox, Mailboxes};
+    use hyperx::header::Headers;
+
+    #[test]
+    fn format_single_without_name() {
+        let from = Mailboxes::new().with("kayo@example.com".parse().unwrap());
+
+        let mut headers = Headers::new();
+        headers.set(From(from));
+
+        assert_eq!(format!("{}", headers), "From: kayo@example.com\r\n");
+    }
+
+    #[test]
+    fn format_single_with_name() {
+        let from = Mailboxes::new().with("K. <kayo@example.com>".parse().unwrap());
+
+        let mut headers = Headers::new();
+        headers.set(From(from));
+
+        assert_eq!(format!("{}", headers), "From: K. <kayo@example.com>\r\n");
+    }
+
+    #[test]
+    fn format_multi_without_name() {
+        let from = Mailboxes::new()
+            .with("kayo@example.com".parse().unwrap())
+            .with("pony@domain.tld".parse().unwrap());
+
+        let mut headers = Headers::new();
+        headers.set(From(from));
+
+        assert_eq!(
+            format!("{}", headers),
+            "From: kayo@example.com, pony@domain.tld\r\n"
+        );
+    }
+
+    #[test]
+    fn format_multi_with_name() {
+        let from = vec![
+            "K. <kayo@example.com>".parse().unwrap(),
+            "Pony P. <pony@domain.tld>".parse().unwrap(),
+        ];
+
+        let mut headers = Headers::new();
+        headers.set(From(from.into()));
+
+        assert_eq!(
+            format!("{}", headers),
+            "From: K. <kayo@example.com>, Pony P. <pony@domain.tld>\r\n"
+        );
+    }
+
+    #[test]
+    fn format_single_with_utf8_name() {
+        let from = vec!["Кайо <kayo@example.com>".parse().unwrap()];
+
+        let mut headers = Headers::new();
+        headers.set(From(from.into()));
+
+        assert_eq!(
+            format!("{}", headers),
+            "From: =?utf-8?b?0JrQsNC50L4=?= <kayo@example.com>\r\n"
+        );
+    }
+
+    #[test]
+    fn parse_single_without_name() {
+        let from = vec!["kayo@example.com".parse().unwrap()].into();
+
+        let mut headers = Headers::new();
+        headers.set_raw("From", "kayo@example.com");
+
+        assert_eq!(headers.get::<From>(), Some(&From(from)));
+    }
+
+    #[test]
+    fn parse_single_with_name() {
+        let from = vec!["K. <kayo@example.com>".parse().unwrap()].into();
+
+        let mut headers = Headers::new();
+        headers.set_raw("From", "K. <kayo@example.com>");
+
+        assert_eq!(headers.get::<From>(), Some(&From(from)));
+    }
+
+    #[test]
+    fn parse_multi_without_name() {
+        let from: Vec<Mailbox> = vec![
+            "kayo@example.com".parse().unwrap(),
+            "pony@domain.tld".parse().unwrap(),
+        ];
+
+        let mut headers = Headers::new();
+        headers.set_raw("From", "kayo@example.com, pony@domain.tld");
+
+        assert_eq!(headers.get::<From>(), Some(&From(from.into())));
+    }
+
+    #[test]
+    fn parse_multi_with_name() {
+        let from: Vec<Mailbox> = vec![
+            "K. <kayo@example.com>".parse().unwrap(),
+            "Pony P. <pony@domain.tld>".parse().unwrap(),
+        ];
+
+        let mut headers = Headers::new();
+        headers.set_raw("From", "K. <kayo@example.com>, Pony P. <pony@domain.tld>");
+
+        assert_eq!(headers.get::<From>(), Some(&From(from.into())));
+    }
+
+    #[test]
+    fn parse_single_with_utf8_name() {
+        let from: Vec<Mailbox> = vec!["Кайо <kayo@example.com>".parse().unwrap()];
+
+        let mut headers = Headers::new();
+        headers.set_raw("From", "=?utf-8?b?0JrQsNC50L4=?= <kayo@example.com>");
+
+        assert_eq!(headers.get::<From>(), Some(&From(from.into())));
+    }
+}

src/message/header/mod.rs

@@ -0,0 +1,17 @@
+/*!
+
+## Headers widely used in email messages
+
+*/
+
+mod content;
+mod mailbox;
+mod special;
+mod textual;
+
+pub use self::{content::*, mailbox::*, special::*, textual::*};
+
+pub use hyperx::header::{
+    Charset, ContentDisposition, ContentLocation, ContentType, Date, DispositionParam,
+    DispositionType, Header, Headers, HttpDate as EmailDate,
+};

src/message/header/special.rs

@@ -0,0 +1,86 @@
+use hyperx::{
+    header::{Formatter as HeaderFormatter, Header, RawLike},
+    Error as HeaderError, Result as HyperResult,
+};
+use std::{fmt::Result as FmtResult, str::from_utf8};
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub struct MimeVersion {
+    pub major: u8,
+    pub minor: u8,
+}
+
+pub const MIME_VERSION_1_0: MimeVersion = MimeVersion { major: 1, minor: 0 };
+
+impl MimeVersion {
+    pub fn new(major: u8, minor: u8) -> Self {
+        MimeVersion { major, minor }
+    }
+}
+
+impl Default for MimeVersion {
+    fn default() -> Self {
+        MIME_VERSION_1_0
+    }
+}
+
+impl Header for MimeVersion {
+    fn header_name() -> &'static str {
+        "MIME-Version"
+    }
+
+    fn parse_header<'a, T>(raw: &'a T) -> HyperResult<Self>
+    where
+        T: RawLike<'a>,
+        Self: Sized,
+    {
+        raw.one().ok_or(HeaderError::Header).and_then(|r| {
+            let s: Vec<&str> = from_utf8(r)
+                .map_err(|_| HeaderError::Header)?
+                .split('.')
+                .collect();
+            if s.len() != 2 {
+                return Err(HeaderError::Header);
+            }
+            let major = s[0].parse().map_err(|_| HeaderError::Header)?;
+            let minor = s[1].parse().map_err(|_| HeaderError::Header)?;
+            Ok(MimeVersion::new(major, minor))
+        })
+    }
+
+    fn fmt_header(&self, f: &mut HeaderFormatter) -> FmtResult {
+        f.fmt_line(&format!("{}.{}", self.major, self.minor))
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::{MimeVersion, MIME_VERSION_1_0};
+    use hyperx::header::Headers;
+
+    #[test]
+    fn format_mime_version() {
+        let mut headers = Headers::new();
+
+        headers.set(MIME_VERSION_1_0);
+
+        assert_eq!(format!("{}", headers), "MIME-Version: 1.0\r\n");
+
+        headers.set(MimeVersion::new(0, 1));
+
+        assert_eq!(format!("{}", headers), "MIME-Version: 0.1\r\n");
+    }
+
+    #[test]
+    fn parse_mime_version() {
+        let mut headers = Headers::new();
+
+        headers.set_raw("MIME-Version", "1.0");
+
+        assert_eq!(headers.get::<MimeVersion>(), Some(&MIME_VERSION_1_0));
+
+        headers.set_raw("MIME-Version", "0.1");
+
+        assert_eq!(headers.get::<MimeVersion>(), Some(&MimeVersion::new(0, 1)));
+    }
+}

src/message/header/textual.rs

@@ -0,0 +1,105 @@
+use crate::message::utf8_b;
+use hyperx::{
+    header::{Formatter as HeaderFormatter, Header, RawLike},
+    Error as HeaderError, Result as HyperResult,
+};
+use std::{fmt::Result as FmtResult, str::from_utf8};
+
+macro_rules! text_header {
+    ( $type_name: ident, $header_name: expr ) => {
+        #[derive(Debug, Clone, PartialEq)]
+        pub struct $type_name(pub String);
+
+        impl Header for $type_name {
+            fn header_name() -> &'static str {
+                $header_name
+            }
+
+            fn parse_header<'a, T>(raw: &'a T) -> HyperResult<$type_name>
+            where
+                T: RawLike<'a>,
+                Self: Sized,
+            {
+                raw.one()
+                    .ok_or(HeaderError::Header)
+                    .and_then(parse_text)
+                    .map($type_name)
+            }
+
+            fn fmt_header(&self, f: &mut HeaderFormatter) -> FmtResult {
+                fmt_text(&self.0, f)
+            }
+        }
+    };
+}
+
+text_header!(Subject, "Subject");
+text_header!(Comments, "Comments");
+text_header!(Keywords, "Keywords");
+text_header!(InReplyTo, "In-Reply-To");
+text_header!(References, "References");
+text_header!(MessageId, "Message-Id");
+text_header!(UserAgent, "User-Agent");
+
+fn parse_text(raw: &[u8]) -> HyperResult<String> {
+    if let Ok(src) = from_utf8(raw) {
+        if let Some(txt) = utf8_b::decode(src) {
+            return Ok(txt);
+        }
+    }
+    Err(HeaderError::Header)
+}
+
+fn fmt_text(s: &str, f: &mut HeaderFormatter) -> FmtResult {
+    f.fmt_line(&utf8_b::encode(s))
+}
+
+#[cfg(test)]
+mod test {
+    use super::Subject;
+    use hyperx::header::Headers;
+
+    #[test]
+    fn format_ascii() {
+        let mut headers = Headers::new();
+        headers.set(Subject("Sample subject".into()));
+
+        assert_eq!(format!("{}", headers), "Subject: Sample subject\r\n");
+    }
+
+    #[test]
+    fn format_utf8() {
+        let mut headers = Headers::new();
+        headers.set(Subject("Тема сообщения".into()));
+
+        assert_eq!(
+            format!("{}", headers),
+            "Subject: =?utf-8?b?0KLQtdC80LAg0YHQvtC+0LHRidC10L3QuNGP?=\r\n"
+        );
+    }
+
+    #[test]
+    fn parse_ascii() {
+        let mut headers = Headers::new();
+        headers.set_raw("Subject", "Sample subject");
+
+        assert_eq!(
+            headers.get::<Subject>(),
+            Some(&Subject("Sample subject".into()))
+        );
+    }
+
+    #[test]
+    fn parse_utf8() {
+        let mut headers = Headers::new();
+        headers.set_raw(
+            "Subject",
+            "=?utf-8?b?0KLQtdC80LAg0YHQvtC+0LHRidC10L3QuNGP?=",
+        );
+
+        assert_eq!(
+            headers.get::<Subject>(),
+            Some(&Subject("Тема сообщения".into()))
+        );
+    }
+}

src/message/mailbox/mod.rs

@@ -0,0 +1,5 @@
+#[cfg(feature = "serde")]
+mod serde;
+mod types;
+
+pub use self::types::*;

src/message/mailbox/serde.rs

@@ -0,0 +1,215 @@
+use crate::message::{Mailbox, Mailboxes};
+use serde::{
+    de::{Deserializer, Error as DeError, MapAccess, SeqAccess, Visitor},
+    ser::Serializer,
+    Deserialize, Serialize,
+};
+use std::fmt::{Formatter, Result as FmtResult};
+
+impl Serialize for Mailbox {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_str(&self.to_string())
+    }
+}
+
+impl<'de> Deserialize<'de> for Mailbox {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        enum Field {
+            Name,
+            Email,
+        };
+
+        const FIELDS: &[&str] = &["name", "email"];
+
+        impl<'de> Deserialize<'de> for Field {
+            fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+            where
+                D: Deserializer<'de>,
+            {
+                struct FieldVisitor;
+
+                impl<'de> Visitor<'de> for FieldVisitor {
+                    type Value = Field;
+
+                    fn expecting(&self, formatter: &mut Formatter) -> FmtResult {
+                        formatter.write_str("'name' or 'email'")
+                    }
+
+                    fn visit_str<E>(self, value: &str) -> Result<Field, E>
+                    where
+                        E: DeError,
+                    {
+                        match value {
+                            "name" => Ok(Field::Name),
+                            "email" => Ok(Field::Email),
+                            _ => Err(DeError::unknown_field(value, FIELDS)),
+                        }
+                    }
+                }
+
+                deserializer.deserialize_identifier(FieldVisitor)
+            }
+        }
+
+        struct MailboxVisitor;
+
+        impl<'de> Visitor<'de> for MailboxVisitor {
+            type Value = Mailbox;
+
+            fn expecting(&self, formatter: &mut Formatter) -> FmtResult {
+                formatter.write_str("mailbox string or object")
+            }
+
+            fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
+            where
+                E: DeError,
+            {
+                s.parse().map_err(DeError::custom)
+            }
+
+            fn visit_map<V>(self, mut map: V) -> Result<Self::Value, V::Error>
+            where
+                V: MapAccess<'de>,
+            {
+                let mut name = None;
+                let mut addr = None;
+                while let Some(key) = map.next_key()? {
+                    match key {
+                        Field::Name => {
+                            if name.is_some() {
+                                return Err(DeError::duplicate_field("name"));
+                            }
+                            name = Some(map.next_value()?);
+                        }
+                        Field::Email => {
+                            if addr.is_some() {
+                                return Err(DeError::duplicate_field("email"));
+                            }
+                            addr = Some(map.next_value()?);
+                        }
+                    }
+                }
+                let addr = addr.ok_or_else(|| DeError::missing_field("email"))?;
+                Ok(Mailbox::new(name, addr))
+            }
+        }
+
+        deserializer.deserialize_any(MailboxVisitor)
+    }
+}
+
+impl Serialize for Mailboxes {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_str(&self.to_string())
+    }
+}
+
+impl<'de> Deserialize<'de> for Mailboxes {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        struct MailboxesVisitor;
+
+        impl<'de> Visitor<'de> for MailboxesVisitor {
+            type Value = Mailboxes;
+
+            fn expecting(&self, formatter: &mut Formatter) -> FmtResult {
+                formatter.write_str("mailboxes string or sequence")
+            }
+
+            fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
+            where
+                E: DeError,
+            {
+                s.parse().map_err(DeError::custom)
+            }
+
+            fn visit_seq<V>(self, mut seq: V) -> Result<Self::Value, V::Error>
+            where
+                V: SeqAccess<'de>,
+            {
+                let mut mboxes = Mailboxes::new();
+                while let Some(mbox) = seq.next_element()? {
+                    mboxes.push(mbox);
+                }
+                Ok(mboxes)
+            }
+        }
+
+        deserializer.deserialize_any(MailboxesVisitor)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::address::Address;
+    use serde_json::from_str;
+
+    #[test]
+    fn parse_address_string() {
+        let m: Address = from_str(r#""kayo@example.com""#).unwrap();
+        assert_eq!(m, "kayo@example.com".parse().unwrap());
+    }
+
+    #[test]
+    fn parse_address_object() {
+        let m: Address = from_str(r#"{ "user": "kayo", "domain": "example.com" }"#).unwrap();
+        assert_eq!(m, "kayo@example.com".parse().unwrap());
+    }
+
+    #[test]
+    fn parse_mailbox_string() {
+        let m: Mailbox = from_str(r#""Kai <kayo@example.com>""#).unwrap();
+        assert_eq!(m, "Kai <kayo@example.com>".parse().unwrap());
+    }
+
+    #[test]
+    fn parse_mailbox_object_address_stirng() {
+        let m: Mailbox = from_str(r#"{ "name": "Kai", "email": "kayo@example.com" }"#).unwrap();
+        assert_eq!(m, "Kai <kayo@example.com>".parse().unwrap());
+    }
+
+    #[test]
+    fn parse_mailbox_object_address_object() {
+        let m: Mailbox =
+            from_str(r#"{ "name": "Kai", "email": { "user": "kayo", "domain": "example.com" } }"#)
+                .unwrap();
+        assert_eq!(m, "Kai <kayo@example.com>".parse().unwrap());
+    }
+
+    #[test]
+    fn parse_mailboxes_string() {
+        let m: Mailboxes =
+            from_str(r#""yin@dtb.com, Hei <hei@dtb.com>, Kai <kayo@example.com>""#).unwrap();
+        assert_eq!(
+            m,
+            "<yin@dtb.com>, Hei <hei@dtb.com>, Kai <kayo@example.com>"
+                .parse()
+                .unwrap()
+        );
+    }
+
+    #[test]
+    fn parse_mailboxes_array() {
+        let m: Mailboxes =
+            from_str(r#"["yin@dtb.com", { "name": "Hei", "email": "hei@dtb.com" }, { "name": "Kai", "email": { "user": "kayo", "domain": "example.com" } }]"#)
+                .unwrap();
+        assert_eq!(
+            m,
+            "<yin@dtb.com>, Hei <hei@dtb.com>, Kai <kayo@example.com>"
+                .parse()
+                .unwrap()
+        );
+    }
+}

src/message/mailbox/types.rs

@@ -0,0 +1,319 @@
+use crate::{
+    address::{Address, AddressError},
+    message::utf8_b,
+};
+use std::{
+    convert::TryFrom,
+    fmt::{Display, Formatter, Result as FmtResult, Write},
+    slice::Iter,
+    str::FromStr,
+};
+
+/// Email address with optional addressee name
+///
+/// This type contains email address and the sender/recipient name (_Some Name \<user@domain.tld\>_ or _withoutname@domain.tld_).
+///
+/// **NOTE**: Enable feature "serde" to be able serialize/deserialize it using [serde](https://serde.rs/).
+#[derive(Debug, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]
+pub struct Mailbox {
+    /// User name part
+    pub name: Option<String>,
+
+    /// Email address part
+    pub email: Address,
+}
+
+impl Mailbox {
+    /// Create new mailbox using email address and addressee name
+    pub fn new(name: Option<String>, email: Address) -> Self {
+        Mailbox { name, email }
+    }
+
+    /// Encode addressee name using function
+    pub(crate) fn recode_name<F>(&self, f: F) -> Self
+    where
+        F: FnOnce(&str) -> String,
+    {
+        Mailbox::new(self.name.clone().map(|s| f(&s)), self.email.clone())
+    }
+}
+
+impl Display for Mailbox {
+    fn fmt(&self, f: &mut Formatter) -> FmtResult {
+        if let Some(ref name) = self.name {
+            let name = name.trim();
+            if !name.is_empty() {
+                f.write_str(&name)?;
+                f.write_str(" <")?;
+                self.email.fmt(f)?;
+                return f.write_char('>');
+            }
+        }
+        self.email.fmt(f)
+    }
+}
+
+impl<S: Into<String>, T: Into<String>> TryFrom<(S, T)> for Mailbox {
+    type Error = AddressError;
+
+    fn try_from(header: (S, T)) -> Result<Self, Self::Error> {
+        let (name, address) = header;
+        Ok(Mailbox::new(Some(name.into()), address.into().parse()?))
+    }
+}
+
+/*
+impl<S: AsRef<&str>, T: AsRef<&str>> TryFrom<(S, T)> for Mailbox {
+    type Error = AddressError;
+
+    fn try_from(header: (S, T)) -> Result<Self, Self::Error> {
+        let (name, address) = header;
+        Ok(Mailbox::new(Some(name.as_ref()), address.as_ref().parse()?))
+    }
+}*/
+
+impl FromStr for Mailbox {
+    type Err = AddressError;
+
+    fn from_str(src: &str) -> Result<Mailbox, Self::Err> {
+        match (src.find('<'), src.find('>')) {
+            (Some(addr_open), Some(addr_close)) if addr_open < addr_close => {
+                let name = src.split_at(addr_open).0;
+                let addr_open = addr_open + 1;
+                let addr = src.split_at(addr_open).1.split_at(addr_close - addr_open).0;
+                let addr = addr.parse()?;
+                let name = name.trim();
+                let name = if name.is_empty() {
+                    None
+                } else {
+                    Some(name.into())
+                };
+                Ok(Mailbox::new(name, addr))
+            }
+            (Some(_), _) => Err(AddressError::Unbalanced),
+            _ => {
+                let addr = src.parse()?;
+                Ok(Mailbox::new(None, addr))
+            }
+        }
+    }
+}
+
+/// List or email mailboxes
+///
+/// This type contains a sequence of mailboxes (_Some Name \<user@domain.tld\>, Another Name \<other@domain.tld\>, withoutname@domain.tld, ..._).
+///
+/// **NOTE**: Enable feature "serde" to be able serialize/deserialize it using [serde](https://serde.rs/).
+#[derive(Debug, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]
+pub struct Mailboxes(Vec<Mailbox>);
+
+impl Mailboxes {
+    /// Create mailboxes list
+    pub fn new() -> Self {
+        Mailboxes(Vec::new())
+    }
+
+    /// Add mailbox to a list
+    pub fn with(mut self, mbox: Mailbox) -> Self {
+        self.0.push(mbox);
+        self
+    }
+
+    /// Add mailbox to a list
+    pub fn push(&mut self, mbox: Mailbox) {
+        self.0.push(mbox);
+    }
+
+    /// Extract first mailbox
+    pub fn into_single(self) -> Option<Mailbox> {
+        self.into()
+    }
+
+    /// Iterate over mailboxes
+    pub fn iter(&self) -> Iter<Mailbox> {
+        self.0.iter()
+    }
+}
+
+impl Default for Mailboxes {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl From<Mailbox> for Mailboxes {
+    fn from(single: Mailbox) -> Self {
+        Mailboxes(vec![single])
+    }
+}
+
+impl Into<Option<Mailbox>> for Mailboxes {
+    fn into(self) -> Option<Mailbox> {
+        self.into_iter().next()
+    }
+}
+
+impl From<Vec<Mailbox>> for Mailboxes {
+    fn from(list: Vec<Mailbox>) -> Self {
+        Mailboxes(list)
+    }
+}
+
+impl Into<Vec<Mailbox>> for Mailboxes {
+    fn into(self) -> Vec<Mailbox> {
+        self.0
+    }
+}
+
+impl IntoIterator for Mailboxes {
+    type Item = Mailbox;
+    type IntoIter = ::std::vec::IntoIter<Mailbox>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.0.into_iter()
+    }
+}
+
+impl Extend<Mailbox> for Mailboxes {
+    fn extend<T: IntoIterator<Item = Mailbox>>(&mut self, iter: T) {
+        for elem in iter {
+            self.0.push(elem);
+        }
+    }
+}
+
+impl Display for Mailboxes {
+    fn fmt(&self, f: &mut Formatter) -> FmtResult {
+        let mut iter = self.iter();
+
+        if let Some(mbox) = iter.next() {
+            mbox.fmt(f)?;
+
+            for mbox in iter {
+                f.write_str(", ")?;
+                mbox.fmt(f)?;
+            }
+        }
+
+        Ok(())
+    }
+}
+
+impl FromStr for Mailboxes {
+    type Err = AddressError;
+
+    fn from_str(src: &str) -> Result<Self, Self::Err> {
+        src.split(',')
+            .map(|m| {
+                m.trim().parse().and_then(|Mailbox { name, email }| {
+                    if let Some(name) = name {
+                        if let Some(name) = utf8_b::decode(&name) {
+                            Ok(Mailbox::new(Some(name), email))
+                        } else {
+                            Err(AddressError::InvalidUtf8b)
+                        }
+                    } else {
+                        Ok(Mailbox::new(None, email))
+                    }
+                })
+            })
+            .collect::<Result<Vec<_>, _>>()
+            .map(Mailboxes)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::Mailbox;
+    use std::convert::TryInto;
+
+    #[test]
+    fn mailbox_format_address_only() {
+        assert_eq!(
+            format!(
+                "{}",
+                Mailbox::new(None, "kayo@example.com".parse().unwrap())
+            ),
+            "kayo@example.com"
+        );
+    }
+
+    #[test]
+    fn mailbox_format_address_with_name() {
+        assert_eq!(
+            format!(
+                "{}",
+                Mailbox::new(Some("K.".into()), "kayo@example.com".parse().unwrap())
+            ),
+            "K. <kayo@example.com>"
+        );
+    }
+
+    #[test]
+    fn format_address_with_empty_name() {
+        assert_eq!(
+            format!(
+                "{}",
+                Mailbox::new(Some("".into()), "kayo@example.com".parse().unwrap())
+            ),
+            "kayo@example.com"
+        );
+    }
+
+    #[test]
+    fn format_address_with_name_trim() {
+        assert_eq!(
+            format!(
+                "{}",
+                Mailbox::new(Some(" K. ".into()), "kayo@example.com".parse().unwrap())
+            ),
+            "K. <kayo@example.com>"
+        );
+    }
+
+    #[test]
+    fn parse_address_only() {
+        assert_eq!(
+            "kayo@example.com".parse(),
+            Ok(Mailbox::new(None, "kayo@example.com".parse().unwrap()))
+        );
+    }
+
+    #[test]
+    fn parse_address_with_name() {
+        assert_eq!(
+            "K. <kayo@example.com>".parse(),
+            Ok(Mailbox::new(
+                Some("K.".into()),
+                "kayo@example.com".parse().unwrap()
+            ))
+        );
+    }
+
+    #[test]
+    fn parse_address_with_empty_name() {
+        assert_eq!(
+            "<kayo@example.com>".parse(),
+            Ok(Mailbox::new(None, "kayo@example.com".parse().unwrap()))
+        );
+    }
+
+    #[test]
+    fn parse_address_with_empty_name_trim() {
+        assert_eq!(
+            " <kayo@example.com>".parse(),
+            Ok(Mailbox::new(None, "kayo@example.com".parse().unwrap()))
+        );
+    }
+
+    #[test]
+    fn parse_address_from_tuple() {
+        assert_eq!(
+            ("K.".to_string(), "kayo@example.com".to_string()).try_into(),
+            Ok(Mailbox::new(
+                Some("K.".into()),
+                "kayo@example.com".parse().unwrap()
+            ))
+        );
+    }
+}

src/message/mimebody.rs

@@ -0,0 +1,604 @@
+use crate::message::{
+    encoder::codec,
+    header::{ContentTransferEncoding, ContentType, Header, Headers},
+    EmailFormat,
+};
+use mime::Mime;
+use textnonce::TextNonce;
+
+/// MIME part variants
+///
+#[derive(Debug, Clone)]
+pub enum Part {
+    /// Single part with content
+    ///
+    Single(SinglePart),
+
+    /// Multiple parts of content
+    ///
+    Multi(MultiPart),
+}
+
+impl EmailFormat for Part {
+    fn format(&self, out: &mut Vec<u8>) {
+        match self {
+            Part::Single(part) => part.format(out),
+            Part::Multi(part) => part.format(out),
+        }
+    }
+}
+
+impl Part {
+    /// Get message content formatted for SMTP
+    pub fn formatted(&self) -> Vec<u8> {
+        let mut out = Vec::new();
+        self.format(&mut out);
+        out
+    }
+}
+
+/// Parts of multipart body
+///
+pub type Parts = Vec<Part>;
+
+/// Creates builder for single part
+///
+#[derive(Debug, Clone)]
+pub struct SinglePartBuilder {
+    headers: Headers,
+}
+
+impl SinglePartBuilder {
+    /// Creates a default singlepart builder
+    pub fn new() -> Self {
+        Self {
+            headers: Headers::new(),
+        }
+    }
+
+    /// Set the header to singlepart
+    pub fn header<H: Header>(mut self, header: H) -> Self {
+        self.headers.set(header);
+        self
+    }
+
+    /// Set the Content-Type header of the singlepart
+    pub fn content_type(mut self, content_type: ContentType) -> Self {
+        self.headers.set(content_type);
+        self
+    }
+
+    /// Build singlepart using body
+    pub fn body<T: Into<Vec<u8>>>(self, body: T) -> SinglePart {
+        SinglePart {
+            headers: self.headers,
+            body: body.into(),
+        }
+    }
+}
+
+impl Default for SinglePartBuilder {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+/// Single part
+///
+/// # Example
+///
+/// ```
+/// use lettre::message::{SinglePart, header};
+///
+/// let part = SinglePart::builder()
+///      .header(header::ContentType("text/plain; charset=utf8".parse().unwrap()))
+///      .header(header::ContentTransferEncoding::Binary)
+///      .body("Текст письма в уникоде");
+/// ```
+///
+#[derive(Debug, Clone)]
+pub struct SinglePart {
+    headers: Headers,
+    body: Vec<u8>,
+}
+
+impl SinglePart {
+    /// Creates a default builder for singlepart
+    pub fn builder() -> SinglePartBuilder {
+        SinglePartBuilder::new()
+    }
+
+    /// Creates a singlepart builder with 7bit encoding
+    ///
+    /// Shortcut for `SinglePart::builder().header(ContentTransferEncoding::SevenBit)`.
+    pub fn seven_bit() -> SinglePartBuilder {
+        Self::builder().header(ContentTransferEncoding::SevenBit)
+    }
+
+    /// Creates a singlepart builder with quoted-printable encoding
+    ///
+    /// Shortcut for `SinglePart::builder().header(ContentTransferEncoding::QuotedPrintable)`.
+    pub fn quoted_printable() -> SinglePartBuilder {
+        Self::builder().header(ContentTransferEncoding::QuotedPrintable)
+    }
+
+    /// Creates a singlepart builder with base64 encoding
+    ///
+    /// Shortcut for `SinglePart::builder().header(ContentTransferEncoding::Base64)`.
+    pub fn base64() -> SinglePartBuilder {
+        Self::builder().header(ContentTransferEncoding::Base64)
+    }
+
+    /// Creates a singlepart builder with 8-bit encoding
+    ///
+    /// Shortcut for `SinglePart::builder().header(ContentTransferEncoding::EightBit)`.
+    pub fn eight_bit() -> SinglePartBuilder {
+        Self::builder().header(ContentTransferEncoding::EightBit)
+    }
+
+    /// Creates a singlepart builder with binary encoding
+    ///
+    /// Shortcut for `SinglePart::builder().header(ContentTransferEncoding::Binary)`.
+    pub fn binary() -> SinglePartBuilder {
+        Self::builder().header(ContentTransferEncoding::Binary)
+    }
+
+    /// Get the headers from singlepart
+    pub fn headers(&self) -> &Headers {
+        &self.headers
+    }
+
+    /// Read the body from singlepart
+    pub fn body_ref(&self) -> &[u8] {
+        &self.body
+    }
+
+    /// Get message content formatted for SMTP
+    pub fn formatted(&self) -> Vec<u8> {
+        let mut out = Vec::new();
+        self.format(&mut out);
+        out
+    }
+}
+
+impl EmailFormat for SinglePart {
+    fn format(&self, out: &mut Vec<u8>) {
+        out.extend_from_slice(self.headers.to_string().as_bytes());
+        out.extend_from_slice(b"\r\n");
+
+        let encoding = self.headers.get::<ContentTransferEncoding>();
+        let mut encoder = codec(encoding);
+
+        out.extend_from_slice(&encoder.encode(&self.body));
+        out.extend_from_slice(b"\r\n");
+    }
+}
+
+/// The kind of multipart
+///
+#[derive(Debug, Clone, Copy)]
+pub enum MultiPartKind {
+    /// Mixed kind to combine unrelated content parts
+    ///
+    /// For example this kind can be used to mix email message and attachments.
+    Mixed,
+
+    /// Alternative kind to join several variants of same email contents.
+    ///
+    /// That kind is recommended to use for joining plain (text) and rich (HTML) messages into single email message.
+    Alternative,
+
+    /// Related kind to mix content and related resources.
+    ///
+    /// For example, you can include images into HTML content using that.
+    Related,
+}
+
+impl MultiPartKind {
+    fn to_mime<S: AsRef<str>>(self, boundary: Option<S>) -> Mime {
+        let boundary = boundary
+            .map(|s| s.as_ref().into())
+            .unwrap_or_else(|| TextNonce::sized(68).unwrap().into_string());
+
+        use self::MultiPartKind::*;
+        format!(
+            "multipart/{}; boundary=\"{}\"",
+            match self {
+                Mixed => "mixed",
+                Alternative => "alternative",
+                Related => "related",
+            },
+            boundary
+        )
+        .parse()
+        .unwrap()
+    }
+
+    fn from_mime(m: &Mime) -> Option<Self> {
+        use self::MultiPartKind::*;
+        match m.subtype().as_ref() {
+            "mixed" => Some(Mixed),
+            "alternative" => Some(Alternative),
+            "related" => Some(Related),
+            _ => None,
+        }
+    }
+}
+
+impl From<MultiPartKind> for Mime {
+    fn from(m: MultiPartKind) -> Self {
+        m.to_mime::<String>(None)
+    }
+}
+
+/// Multipart builder
+///
+#[derive(Debug, Clone)]
+pub struct MultiPartBuilder {
+    headers: Headers,
+}
+
+impl MultiPartBuilder {
+    /// Creates default multipart builder
+    pub fn new() -> Self {
+        Self {
+            headers: Headers::new(),
+        }
+    }
+
+    /// Set a header
+    pub fn header<H: Header>(mut self, header: H) -> Self {
+        self.headers.set(header);
+        self
+    }
+
+    /// Set `Content-Type` header using [`MultiPartKind`]
+    pub fn kind(self, kind: MultiPartKind) -> Self {
+        self.header(ContentType(kind.into()))
+    }
+
+    /// Set custom boundary
+    pub fn boundary<S: AsRef<str>>(self, boundary: S) -> Self {
+        let kind = {
+            let mime = &self.headers.get::<ContentType>().unwrap().0;
+            MultiPartKind::from_mime(mime).unwrap()
+        };
+        let mime = kind.to_mime(Some(boundary.as_ref()));
+        self.header(ContentType(mime))
+    }
+
+    /// Creates multipart without parts
+    pub fn build(self) -> MultiPart {
+        MultiPart {
+            headers: self.headers,
+            parts: Vec::new(),
+        }
+    }
+
+    /// Creates multipart using part
+    pub fn part(self, part: Part) -> MultiPart {
+        self.build().part(part)
+    }
+
+    /// Creates multipart using singlepart
+    pub fn singlepart(self, part: SinglePart) -> MultiPart {
+        self.build().singlepart(part)
+    }
+
+    /// Creates multipart using multipart
+    pub fn multipart(self, part: MultiPart) -> MultiPart {
+        self.build().multipart(part)
+    }
+}
+
+impl Default for MultiPartBuilder {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+/// Multipart variant with parts
+///
+#[derive(Debug, Clone)]
+pub struct MultiPart {
+    headers: Headers,
+    parts: Parts,
+}
+
+impl MultiPart {
+    /// Creates multipart builder
+    pub fn builder() -> MultiPartBuilder {
+        MultiPartBuilder::new()
+    }
+
+    /// Creates mixed multipart builder
+    ///
+    /// Shortcut for `MultiPart::builder().kind(MultiPartKind::Mixed)`
+    pub fn mixed() -> MultiPartBuilder {
+        MultiPart::builder().kind(MultiPartKind::Mixed)
+    }
+
+    /// Creates alternative multipart builder
+    ///
+    /// Shortcut for `MultiPart::builder().kind(MultiPartKind::Alternative)`
+    pub fn alternative() -> MultiPartBuilder {
+        MultiPart::builder().kind(MultiPartKind::Alternative)
+    }
+
+    /// Creates related multipart builder
+    ///
+    /// Shortcut for `MultiPart::builder().kind(MultiPartKind::Related)`
+    pub fn related() -> MultiPartBuilder {
+        MultiPart::builder().kind(MultiPartKind::Related)
+    }
+
+    /// Add part to multipart
+    pub fn part(mut self, part: Part) -> Self {
+        self.parts.push(part);
+        self
+    }
+
+    /// Add single part to multipart
+    pub fn singlepart(mut self, part: SinglePart) -> Self {
+        self.parts.push(Part::Single(part));
+        self
+    }
+
+    /// Add multi part to multipart
+    pub fn multipart(mut self, part: MultiPart) -> Self {
+        self.parts.push(Part::Multi(part));
+        self
+    }
+
+    /// Get the boundary of multipart contents
+    pub fn boundary(&self) -> String {
+        let content_type = &self.headers.get::<ContentType>().unwrap().0;
+        content_type.get_param("boundary").unwrap().as_str().into()
+    }
+
+    /// Get the headers from the multipart
+    pub fn headers(&self) -> &Headers {
+        &self.headers
+    }
+
+    /// Get a mutable reference to the headers
+    pub fn headers_mut(&mut self) -> &mut Headers {
+        &mut self.headers
+    }
+
+    /// Get the parts from the multipart
+    pub fn parts(&self) -> &Parts {
+        &self.parts
+    }
+
+    /// Get a mutable reference to the parts
+    pub fn parts_mut(&mut self) -> &mut Parts {
+        &mut self.parts
+    }
+
+    /// Get message content formatted for SMTP
+    pub fn formatted(&self) -> Vec<u8> {
+        let mut out = Vec::new();
+        self.format(&mut out);
+        out
+    }
+}
+
+impl EmailFormat for MultiPart {
+    fn format(&self, out: &mut Vec<u8>) {
+        out.extend_from_slice(self.headers.to_string().as_bytes());
+        out.extend_from_slice(b"\r\n");
+
+        let boundary = self.boundary();
+
+        for part in &self.parts {
+            out.extend_from_slice(b"--");
+            out.extend_from_slice(boundary.as_bytes());
+            out.extend_from_slice(b"\r\n");
+            part.format(out);
+        }
+
+        out.extend_from_slice(b"--");
+        out.extend_from_slice(boundary.as_bytes());
+        out.extend_from_slice(b"--\r\n");
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::message::header;
+
+    #[test]
+    fn single_part_binary() {
+        let part = SinglePart::builder()
+            .header(header::ContentType(
+                "text/plain; charset=utf8".parse().unwrap(),
+            ))
+            .header(header::ContentTransferEncoding::Binary)
+            .body(String::from("Текст письма в уникоде"));
+
+        assert_eq!(
+            String::from_utf8(part.formatted()).unwrap(),
+            concat!(
+                "Content-Type: text/plain; charset=utf8\r\n",
+                "Content-Transfer-Encoding: binary\r\n",
+                "\r\n",
+                "Текст письма в уникоде\r\n"
+            )
+        );
+    }
+
+    #[test]
+    fn single_part_quoted_printable() {
+        let part = SinglePart::builder()
+            .header(header::ContentType(
+                "text/plain; charset=utf8".parse().unwrap(),
+            ))
+            .header(header::ContentTransferEncoding::QuotedPrintable)
+            .body(String::from("Текст письма в уникоде"));
+
+        assert_eq!(
+            String::from_utf8(part.formatted()).unwrap(),
+            concat!(
+                "Content-Type: text/plain; charset=utf8\r\n",
+                "Content-Transfer-Encoding: quoted-printable\r\n",
+                "\r\n",
+                "=D0=A2=D0=B5=D0=BA=D1=81=D1=82 =D0=BF=D0=B8=D1=81=D1=8C=D0=BC=D0=B0 =D0=B2 =\r\n",
+                "=D1=83=D0=BD=D0=B8=D0=BA=D0=BE=D0=B4=D0=B5\r\n"
+            )
+        );
+    }
+
+    #[test]
+    fn single_part_base64() {
+        let part = SinglePart::builder()
+            .header(header::ContentType(
+                "text/plain; charset=utf8".parse().unwrap(),
+            ))
+            .header(header::ContentTransferEncoding::Base64)
+            .body(String::from("Текст письма в уникоде"));
+
+        assert_eq!(
+            String::from_utf8(part.formatted()).unwrap(),
+            concat!(
+                "Content-Type: text/plain; charset=utf8\r\n",
+                "Content-Transfer-Encoding: base64\r\n",
+                "\r\n",
+                "0KLQtdC60YHRgiDQv9C40YHRjNC80LAg0LIg0YPQvdC40LrQvtC00LU=\r\n"
+            )
+        );
+    }
+
+    #[test]
+    fn multi_part_mixed() {
+        let part = MultiPart::mixed()
+            .boundary("F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK")
+            .part(Part::Single(
+                SinglePart::builder()
+                    .header(header::ContentType(
+                        "text/plain; charset=utf8".parse().unwrap(),
+                    ))
+                    .header(header::ContentTransferEncoding::Binary)
+                    .body(String::from("Текст письма в уникоде")),
+            ))
+            .singlepart(
+                SinglePart::builder()
+                    .header(header::ContentType(
+                        "text/plain; charset=utf8".parse().unwrap(),
+                    ))
+                    .header(header::ContentDisposition {
+                        disposition: header::DispositionType::Attachment,
+                        parameters: vec![header::DispositionParam::Filename(
+                            header::Charset::Ext("utf-8".into()),
+                            None,
+                            "example.c".as_bytes().into(),
+                        )],
+                    })
+                    .header(header::ContentTransferEncoding::Binary)
+                    .body(String::from("int main() { return 0; }")),
+            );
+
+        assert_eq!(String::from_utf8(part.formatted()).unwrap(),
+                   concat!("Content-Type: multipart/mixed;",
+                           " boundary=\"F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK\"\r\n",
+                           "\r\n",
+                           "--F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK\r\n",
+                           "Content-Type: text/plain; charset=utf8\r\n",
+                           "Content-Transfer-Encoding: binary\r\n",
+                           "\r\n",
+                           "Текст письма в уникоде\r\n",
+                           "--F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK\r\n",
+                           "Content-Type: text/plain; charset=utf8\r\n",
+                           "Content-Disposition: attachment; filename=\"example.c\"\r\n",
+                           "Content-Transfer-Encoding: binary\r\n",
+                           "\r\n",
+                           "int main() { return 0; }\r\n",
+                           "--F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK--\r\n"));
+    }
+
+    #[test]
+    fn multi_part_alternative() {
+        let part = MultiPart::alternative()
+            .boundary("F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK")
+            .part(Part::Single(SinglePart::builder()
+                             .header(header::ContentType("text/plain; charset=utf8".parse().unwrap()))
+                             .header(header::ContentTransferEncoding::Binary)
+                             .body(String::from("Текст письма в уникоде"))))
+            .singlepart(SinglePart::builder()
+                             .header(header::ContentType("text/html; charset=utf8".parse().unwrap()))
+                             .header(header::ContentTransferEncoding::Binary)
+                             .body(String::from("<p>Текст <em>письма</em> в <a href=\"https://ru.wikipedia.org/wiki/Юникод\">уникоде</a><p>")));
+
+        assert_eq!(String::from_utf8(part.formatted()).unwrap(),
+                   concat!("Content-Type: multipart/alternative;",
+                           " boundary=\"F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK\"\r\n",
+                           "\r\n",
+                           "--F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK\r\n",
+                           "Content-Type: text/plain; charset=utf8\r\n",
+                           "Content-Transfer-Encoding: binary\r\n",
+                           "\r\n",
+                           "Текст письма в уникоде\r\n",
+                           "--F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK\r\n",
+                           "Content-Type: text/html; charset=utf8\r\n",
+                           "Content-Transfer-Encoding: binary\r\n",
+                           "\r\n",
+                           "<p>Текст <em>письма</em> в <a href=\"https://ru.wikipedia.org/wiki/Юникод\">уникоде</a><p>\r\n",
+                           "--F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK--\r\n"));
+    }
+
+    #[test]
+    fn multi_part_mixed_related() {
+        let part = MultiPart::mixed()
+            .boundary("F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK")
+            .multipart(MultiPart::related()
+                            .boundary("E912L4JH3loAAAAAFu/33Gx7PEoTMmhGaxG3FlbVMQHctj96q4nHvBM+7DTtXo/im8gh")
+                            .singlepart(SinglePart::builder()
+                                             .header(header::ContentType("text/html; charset=utf8".parse().unwrap()))
+                                             .header(header::ContentTransferEncoding::Binary)
+                                             .body(String::from("<p>Текст <em>письма</em> в <a href=\"https://ru.wikipedia.org/wiki/Юникод\">уникоде</a><p>")))
+                            .singlepart(SinglePart::builder()
+                                             .header(header::ContentType("image/png".parse().unwrap()))
+                                             .header(header::ContentLocation("/image.png".into()))
+                                             .header(header::ContentTransferEncoding::Base64)
+                                             .body(String::from("1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890"))))
+            .singlepart(SinglePart::builder()
+                             .header(header::ContentType("text/plain; charset=utf8".parse().unwrap()))
+                             .header(header::ContentDisposition {
+                                 disposition: header::DispositionType::Attachment,
+                                 parameters: vec![header::DispositionParam::Filename(header::Charset::Ext("utf-8".into()), None, "example.c".as_bytes().into())]
+                             })
+                             .header(header::ContentTransferEncoding::Binary)
+                             .body(String::from("int main() { return 0; }")));
+
+        assert_eq!(String::from_utf8(part.formatted()).unwrap(),
+                   concat!("Content-Type: multipart/mixed;",
+                           " boundary=\"F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK\"\r\n",
+                           "\r\n",
+                           "--F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK\r\n",
+                           "Content-Type: multipart/related;",
+                           " boundary=\"E912L4JH3loAAAAAFu/33Gx7PEoTMmhGaxG3FlbVMQHctj96q4nHvBM+7DTtXo/im8gh\"\r\n",
+                           "\r\n",
+                           "--E912L4JH3loAAAAAFu/33Gx7PEoTMmhGaxG3FlbVMQHctj96q4nHvBM+7DTtXo/im8gh\r\n",
+                           "Content-Type: text/html; charset=utf8\r\n",
+                           "Content-Transfer-Encoding: binary\r\n",
+                           "\r\n",
+                           "<p>Текст <em>письма</em> в <a href=\"https://ru.wikipedia.org/wiki/Юникод\">уникоде</a><p>\r\n",
+                           "--E912L4JH3loAAAAAFu/33Gx7PEoTMmhGaxG3FlbVMQHctj96q4nHvBM+7DTtXo/im8gh\r\n",
+                           "Content-Type: image/png\r\n",
+                           "Content-Location: /image.png\r\n",
+                           "Content-Transfer-Encoding: base64\r\n",
+                           "\r\n",
+                           "MTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0NTY3ODkwMTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0NTY3\r\n",
+                           "ODkwMTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0NTY3ODkwMTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0\r\n",
+                           "NTY3ODkwMTIzNDU2Nzg5MA==\r\n",
+                           "--E912L4JH3loAAAAAFu/33Gx7PEoTMmhGaxG3FlbVMQHctj96q4nHvBM+7DTtXo/im8gh--\r\n",
+                           "--F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK\r\n",
+                           "Content-Type: text/plain; charset=utf8\r\n",
+                           "Content-Disposition: attachment; filename=\"example.c\"\r\n",
+                           "Content-Transfer-Encoding: binary\r\n",
+                           "\r\n",
+                           "int main() { return 0; }\r\n",
+                           "--F2mTKN843loAAAAA8porEdAjCKhArPxGeahYoZYSftse1GT/84tup+O0bs8eueVuAlMK--\r\n"));
+    }
+}

src/message/mod.rs

@@ -0,0 +1,550 @@
+//! Provides a strongly typed way to build emails
+//!
+//! ### Creating messages
+//!
+//! This section explains how to create emails.
+//!
+//! ## Usage
+//!
+//! ### Format email messages
+//!
+//! #### With string body
+//!
+//! The easiest way how we can create email message with simple string.
+//!
+//! ```rust
+//! # extern crate lettre;
+//! use lettre::message::Message;
+//!
+//! let m = Message::builder()
+//!     .from("NoBody <nobody@domain.tld>".parse().unwrap())
+//!     .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+//!     .to("Hei <hei@domain.tld>".parse().unwrap())
+//!     .subject("Happy new year")
+//!     .body("Be happy!")
+//!     .unwrap();
+//! ```
+//!
+//! Will produce:
+//!
+//! ```sh
+//! From: NoBody <nobody@domain.tld>
+//! Reply-To: Yuin <yuin@domain.tld>
+//! To: Hei <hei@domain.tld>
+//! Subject: Happy new year
+//!
+//! Be happy!
+//! ```
+//!
+//! The unicode header data will be encoded using _UTF8-Base64_ encoding.
+//!
+//! ### With MIME body
+//!
+//! ##### Single part
+//!
+//! The more complex way is using MIME contents.
+//!
+//! ```rust
+//! # extern crate lettre;
+//! use lettre::message::{header, Message, SinglePart, Part};
+//!
+//! let m = Message::builder()
+//!     .from("NoBody <nobody@domain.tld>".parse().unwrap())
+//!     .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+//!     .to("Hei <hei@domain.tld>".parse().unwrap())
+//!     .subject("Happy new year")
+//!     .singlepart(
+//!         SinglePart::builder()
+//!             .header(header::ContentType(
+//!                 "text/plain; charset=utf8".parse().unwrap(),
+//!             )).header(header::ContentTransferEncoding::QuotedPrintable)
+//!             .body("Привет, мир!"),
+//!     )
+//!     .unwrap();
+//! ```
+//!
+//! The body will be encoded using selected `Content-Transfer-Encoding`.
+//!
+//! ```sh
+//! From: NoBody <nobody@domain.tld>
+//! Reply-To: Yuin <yuin@domain.tld>
+//! To: Hei <hei@domain.tld>
+//! Subject: Happy new year
+//! MIME-Version: 1.0
+//! Content-Type: text/plain; charset=utf8
+//! Content-Transfer-Encoding: quoted-printable
+//!
+//! =D0=9F=D1=80=D0=B8=D0=B2=D0=B5=D1=82, =D0=BC=D0=B8=D1=80!
+//!
+//! ```
+//!
+//! ##### Multiple parts
+//!
+//! And more advanced way of building message by using multipart MIME contents.
+//!
+//! ```rust
+//! # extern crate lettre;
+//! use lettre::message::{header, Message, MultiPart, SinglePart, Part};
+//!
+//! let m = Message::builder()
+//!     .from("NoBody <nobody@domain.tld>".parse().unwrap())
+//!     .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+//!     .to("Hei <hei@domain.tld>".parse().unwrap())
+//!     .subject("Happy new year")
+//!     .multipart(
+//!         MultiPart::mixed()
+//!         .multipart(
+//!             MultiPart::alternative()
+//!             .singlepart(
+//!                 SinglePart::quoted_printable()
+//!                 .header(header::ContentType("text/plain; charset=utf8".parse().unwrap()))
+//!                 .body("Привет, мир!")
+//!             )
+//!             .multipart(
+//!                MultiPart::related()
+//!                 .singlepart(
+//!                     SinglePart::eight_bit()
+//!                     .header(header::ContentType("text/html; charset=utf8".parse().unwrap()))
+//!                     .body("<p><b>Hello</b>, <i>world</i>! <img src=smile.png></p>")
+//!                 )
+//!                 .singlepart(
+//!                     SinglePart::base64()
+//!                     .header(header::ContentType("image/png".parse().unwrap()))
+//!                     .header(header::ContentDisposition {
+//!                         disposition: header::DispositionType::Inline,
+//!                         parameters: vec![],
+//!                     })
+//!                     .body("<smile-raw-image-data>")
+//!                 )
+//!             )
+//!         )
+//!         .singlepart(
+//!             SinglePart::seven_bit()
+//!             .header(header::ContentType("text/plain; charset=utf8".parse().unwrap()))
+//!             .header(header::ContentDisposition {
+//!                 disposition: header::DispositionType::Attachment,
+//!                 parameters: vec![
+//!                     header::DispositionParam::Filename(
+//!                         header::Charset::Ext("utf-8".into()),
+//!                         None, "example.c".as_bytes().into()
+//!                     )
+//!                 ]
+//!             })
+//!             .body("int main() { return 0; }")
+//!         )
+//!     ).unwrap();
+//! ```
+//!
+//! ```sh
+//! From: NoBody <nobody@domain.tld>
+//! Reply-To: Yuin <yuin@domain.tld>
+//! To: Hei <hei@domain.tld>
+//! Subject: Happy new year
+//! MIME-Version: 1.0
+//! Content-Type: multipart/mixed; boundary="RTxPCn9p31oAAAAAeQxtr1FbXr/i5vW1hFlH9oJqZRMWxRMK1QLjQ4OPqFk9R+0xUb/m"
+//!
+//! --RTxPCn9p31oAAAAAeQxtr1FbXr/i5vW1hFlH9oJqZRMWxRMK1QLjQ4OPqFk9R+0xUb/m
+//! Content-Type: multipart/alternative; boundary="qW9QCn9p31oAAAAAodFBg1L1Qrraa5hEl0bDJ6kfJMUcRT2LLSWEoeyhSEbUBIqbjWqy"
+//!
+//! --qW9QCn9p31oAAAAAodFBg1L1Qrraa5hEl0bDJ6kfJMUcRT2LLSWEoeyhSEbUBIqbjWqy
+//! Content-Transfer-Encoding: quoted-printable
+//! Content-Type: text/plain; charset=utf8
+//!
+//! =D0=9F=D1=80=D0=B8=D0=B2=D0=B5=D1=82, =D0=BC=D0=B8=D1=80!
+//! --qW9QCn9p31oAAAAAodFBg1L1Qrraa5hEl0bDJ6kfJMUcRT2LLSWEoeyhSEbUBIqbjWqy
+//! Content-Type: multipart/related; boundary="BV5RCn9p31oAAAAAUt42E9bYMDEAGCOWlxEz89Bv0qFA5Xsy6rOC3zRahMQ39IFZNnp8"
+//!
+//! --BV5RCn9p31oAAAAAUt42E9bYMDEAGCOWlxEz89Bv0qFA5Xsy6rOC3zRahMQ39IFZNnp8
+//! Content-Transfer-Encoding: 8bit
+//! Content-Type: text/html; charset=utf8
+//!
+//! <p><b>Hello</b>, <i>world</i>! <img src=smile.png></p>
+//! --BV5RCn9p31oAAAAAUt42E9bYMDEAGCOWlxEz89Bv0qFA5Xsy6rOC3zRahMQ39IFZNnp8
+//! Content-Transfer-Encoding: base64
+//! Content-Type: image/png
+//! Content-Disposition: inline
+//!
+//! PHNtaWxlLXJhdy1pbWFnZS1kYXRhPg==
+//! --BV5RCn9p31oAAAAAUt42E9bYMDEAGCOWlxEz89Bv0qFA5Xsy6rOC3zRahMQ39IFZNnp8--
+//! --qW9QCn9p31oAAAAAodFBg1L1Qrraa5hEl0bDJ6kfJMUcRT2LLSWEoeyhSEbUBIqbjWqy--
+//! --RTxPCn9p31oAAAAAeQxtr1FbXr/i5vW1hFlH9oJqZRMWxRMK1QLjQ4OPqFk9R+0xUb/m
+//! Content-Transfer-Encoding: 7bit
+//! Content-Type: text/plain; charset=utf8
+//! Content-Disposition: attachment; filename="example.c"
+//!
+//! int main() { return 0; }
+//! --RTxPCn9p31oAAAAAeQxtr1FbXr/i5vW1hFlH9oJqZRMWxRMK1QLjQ4OPqFk9R+0xUb/m--
+//!
+//! ```
+
+pub use encoder::*;
+pub use mailbox::*;
+pub use mimebody::*;
+
+pub use mime;
+
+mod encoder;
+pub mod header;
+mod mailbox;
+mod mimebody;
+mod utf8_b;
+
+use crate::{
+    message::header::{EmailDate, Header, Headers, MailboxesHeader},
+    Envelope, Error as EmailError,
+};
+use std::{convert::TryFrom, time::SystemTime};
+use uuid::Uuid;
+
+const DEFAULT_MESSAGE_ID_DOMAIN: &str = "localhost";
+
+pub trait EmailFormat {
+    // Use a writer?
+    fn format(&self, out: &mut Vec<u8>);
+}
+
+/// A builder for messages
+#[derive(Debug, Clone)]
+pub struct MessageBuilder {
+    headers: Headers,
+    envelope: Option<Envelope>,
+}
+
+impl MessageBuilder {
+    /// Creates a new default message builder
+    pub fn new() -> Self {
+        Self {
+            headers: Headers::new(),
+            envelope: None,
+        }
+    }
+
+    /// Set custom header to message
+    pub fn header<H: Header>(mut self, header: H) -> Self {
+        self.headers.set(header);
+        self
+    }
+
+    /// Add mailbox to header
+    pub fn mailbox<H: Header + MailboxesHeader>(mut self, header: H) -> Self {
+        if self.headers.has::<H>() {
+            self.headers.get_mut::<H>().unwrap().join_mailboxes(header);
+            self
+        } else {
+            self.header(header)
+        }
+    }
+
+    /// Add `Date` header to message
+    ///
+    /// Shortcut for `self.header(header::Date(date))`.
+    pub fn date(self, date: EmailDate) -> Self {
+        self.header(header::Date(date))
+    }
+
+    /// Set `Date` header using current date/time
+    ///
+    /// Shortcut for `self.date(SystemTime::now())`.
+    pub fn date_now(self) -> Self {
+        self.date(SystemTime::now().into())
+    }
+
+    /// Set `Subject` header to message
+    ///
+    /// Shortcut for `self.header(header::Subject(subject.into()))`.
+    pub fn subject<S: Into<String>>(self, subject: S) -> Self {
+        self.header(header::Subject(subject.into()))
+    }
+
+    /// Set `Mime-Version` header to 1.0
+    ///
+    /// Shortcut for `self.header(header::MIME_VERSION_1_0)`.
+    ///
+    /// Not exposed as it is set by body methods
+    fn mime_1_0(self) -> Self {
+        self.header(header::MIME_VERSION_1_0)
+    }
+
+    /// Set `Sender` header. Should be used when providing several `From` mailboxes.
+    ///
+    /// https://tools.ietf.org/html/rfc5322#section-3.6.2
+    ///
+    /// Shortcut for `self.header(header::Sender(mbox))`.
+    pub fn sender(self, mbox: Mailbox) -> Self {
+        self.header(header::Sender(mbox))
+    }
+
+    /// Set or add mailbox to `From` header
+    ///
+    /// https://tools.ietf.org/html/rfc5322#section-3.6.2
+    ///
+    /// Shortcut for `self.mailbox(header::From(mbox))`.
+    pub fn from(self, mbox: Mailbox) -> Self {
+        self.mailbox(header::From(mbox.into()))
+    }
+
+    /// Set or add mailbox to `ReplyTo` header
+    ///
+    /// https://tools.ietf.org/html/rfc5322#section-3.6.2
+    ///
+    /// Shortcut for `self.mailbox(header::ReplyTo(mbox))`.
+    pub fn reply_to(self, mbox: Mailbox) -> Self {
+        self.mailbox(header::ReplyTo(mbox.into()))
+    }
+
+    /// Set or add mailbox to `To` header
+    ///
+    /// Shortcut for `self.mailbox(header::To(mbox))`.
+    pub fn to(self, mbox: Mailbox) -> Self {
+        self.mailbox(header::To(mbox.into()))
+    }
+
+    /// Set or add mailbox to `Cc` header
+    ///
+    /// Shortcut for `self.mailbox(header::Cc(mbox))`.
+    pub fn cc(self, mbox: Mailbox) -> Self {
+        self.mailbox(header::Cc(mbox.into()))
+    }
+
+    /// Set or add mailbox to `Bcc` header
+    ///
+    /// Shortcut for `self.mailbox(header::Bcc(mbox))`.
+    pub fn bcc(self, mbox: Mailbox) -> Self {
+        self.mailbox(header::Bcc(mbox.into()))
+    }
+
+    /// Set or add message id to [`In-Reply-To`
+    /// header](https://tools.ietf.org/html/rfc5322#section-3.6.4)
+    pub fn in_reply_to(self, id: String) -> Self {
+        self.header(header::InReplyTo(id))
+    }
+
+    /// Set or add message id to [`References`
+    /// header](https://tools.ietf.org/html/rfc5322#section-3.6.4)
+    pub fn references(self, id: String) -> Self {
+        self.header(header::References(id))
+    }
+
+    /// Set [Message-Id
+    /// header](https://tools.ietf.org/html/rfc5322#section-3.6.4)
+    ///
+    /// Should generally be inserted by the mail relay.
+    ///
+    /// If `None` is provided, an id will be generated in the
+    /// `<UUID@HOSTNAME>`.
+    pub fn message_id(self, id: Option<String>) -> Self {
+        match id {
+            Some(i) => self.header(header::MessageId(i)),
+            None => {
+                #[cfg(feature = "hostname")]
+                let hostname = hostname::get()
+                    .map_err(|_| ())
+                    .and_then(|s| s.into_string().map_err(|_| ()))
+                    .unwrap_or_else(|_| DEFAULT_MESSAGE_ID_DOMAIN.to_string());
+                #[cfg(not(feature = "hostname"))]
+                let hostname = DEFAULT_MESSAGE_ID_DOMAIN.to_string();
+
+                self.header(header::MessageId(
+                    // https://tools.ietf.org/html/rfc5322#section-3.6.4
+                    format!("<{}@{}>", Uuid::new_v4(), hostname),
+                ))
+            }
+        }
+    }
+
+    /// Set [User-Agent
+    /// header](https://tools.ietf.org/html/draft-melnikov-email-user-agent-004)
+    pub fn user_agent(self, id: String) -> Self {
+        self.header(header::UserAgent(id))
+    }
+
+    /// Force specific envelope (by default it is derived from headers)
+    pub fn envelope(mut self, envelope: Envelope) -> Self {
+        self.envelope = Some(envelope);
+        self
+    }
+
+    // TODO: High-level methods for attachments and embedded files
+
+    /// Create message from body
+    fn build(self, body: Body) -> Result<Message, EmailError> {
+        // Check for missing required headers
+        // https://tools.ietf.org/html/rfc5322#section-3.6
+
+        // Insert Date if missing
+        let res = if self.headers.get::<header::Date>().is_none() {
+            self.date_now()
+        } else {
+            self
+        };
+
+        // Fail is missing correct originator (Sender or From)
+        match res.headers.get::<header::From>() {
+            Some(header::From(f)) => {
+                let from: Vec<Mailbox> = f.clone().into();
+                if from.len() > 1 && res.headers.get::<header::Sender>().is_none() {
+                    return Err(EmailError::TooManyFrom);
+                }
+            }
+            None => {
+                return Err(EmailError::MissingFrom);
+            }
+        }
+
+        let envelope = match res.envelope {
+            Some(e) => e,
+            None => Envelope::try_from(&res.headers)?,
+        };
+        Ok(Message {
+            headers: res.headers,
+            body,
+            envelope,
+        })
+    }
+
+    // In theory having a body is optional
+
+    /// Plain ASCII body
+    ///
+    /// *WARNING*: Generally not what you want
+    pub fn body<T: Into<String>>(self, body: T) -> Result<Message, EmailError> {
+        // 998 chars by line
+        // CR and LF MUST only occur together as CRLF; they MUST NOT appear
+        //  independently in the body.
+        let body = body.into();
+
+        if !&body.is_ascii() {
+            return Err(EmailError::NonAsciiChars);
+        }
+
+        self.build(Body::Raw(body))
+    }
+
+    /// Create message using mime body ([`MultiPart`](::MultiPart))
+    pub fn multipart(self, part: MultiPart) -> Result<Message, EmailError> {
+        self.mime_1_0().build(Body::Mime(Part::Multi(part)))
+    }
+
+    /// Create message using mime body ([`SinglePart`](::SinglePart)
+    pub fn singlepart(self, part: SinglePart) -> Result<Message, EmailError> {
+        self.mime_1_0().build(Body::Mime(Part::Single(part)))
+    }
+}
+
+/// Email message which can be formatted
+#[derive(Clone, Debug)]
+pub struct Message {
+    headers: Headers,
+    body: Body,
+    envelope: Envelope,
+}
+
+#[derive(Clone, Debug)]
+enum Body {
+    Mime(Part),
+    Raw(String),
+}
+
+impl Message {
+    /// Create a new message builder without headers
+    pub fn builder() -> MessageBuilder {
+        MessageBuilder::new()
+    }
+
+    /// Get the headers from the Message
+    pub fn headers(&self) -> &Headers {
+        &self.headers
+    }
+
+    /// Get `Message` envelope
+    pub fn envelope(&self) -> &Envelope {
+        &self.envelope
+    }
+
+    /// Get message content formatted for SMTP
+    pub fn formatted(&self) -> Vec<u8> {
+        let mut out = Vec::new();
+        self.format(&mut out);
+        out
+    }
+}
+
+impl EmailFormat for Message {
+    fn format(&self, out: &mut Vec<u8>) {
+        out.extend_from_slice(self.headers.to_string().as_bytes());
+        match &self.body {
+            Body::Mime(p) => p.format(out),
+            Body::Raw(r) => {
+                out.extend_from_slice(b"\r\n");
+                out.extend(r.as_bytes())
+            }
+        }
+    }
+}
+
+impl Default for MessageBuilder {
+    fn default() -> Self {
+        MessageBuilder::new()
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use crate::message::{header, mailbox::Mailbox, Message};
+
+    #[test]
+    fn email_missing_originator() {
+        assert!(Message::builder().body("Happy new year!").is_err());
+    }
+
+    #[test]
+    fn email_miminal_message() {
+        assert!(Message::builder()
+            .from("NoBody <nobody@domain.tld>".parse().unwrap())
+            .to("NoBody <nobody@domain.tld>".parse().unwrap())
+            .body("Happy new year!")
+            .is_ok());
+    }
+
+    #[test]
+    fn email_missing_sender() {
+        assert!(Message::builder()
+            .from("NoBody <nobody@domain.tld>".parse().unwrap())
+            .from("AnyBody <anybody@domain.tld>".parse().unwrap())
+            .body("Happy new year!")
+            .is_err());
+    }
+
+    #[test]
+    fn email_message() {
+        let date = "Tue, 15 Nov 1994 08:12:31 GMT".parse().unwrap();
+
+        let email = Message::builder()
+            .date(date)
+            .header(header::From(
+                vec![Mailbox::new(
+                    Some("Каи".into()),
+                    "kayo@example.com".parse().unwrap(),
+                )]
+                .into(),
+            ))
+            .header(header::To(
+                vec!["Pony O.P. <pony@domain.tld>".parse().unwrap()].into(),
+            ))
+            .header(header::Subject("яңа ел белән!".into()))
+            .body("Happy new year!")
+            .unwrap();
+
+        assert_eq!(
+            String::from_utf8(email.formatted()).unwrap(),
+            concat!(
+                "Date: Tue, 15 Nov 1994 08:12:31 GMT\r\n",
+                "From: =?utf-8?b?0JrQsNC4?= <kayo@example.com>\r\n",
+                "To: Pony O.P. <pony@domain.tld>\r\n",
+                "Subject: =?utf-8?b?0Y/So9CwINC10Lsg0LHQtdC705nQvSE=?=\r\n",
+                "\r\n",
+                "Happy new year!"
+            )
+        );
+    }
+}

src/message/utf8_b.rs

@@ -0,0 +1,69 @@
+use std::str::from_utf8;
+
+// https://tools.ietf.org/html/rfc1522
+
+fn allowed_char(c: char) -> bool {
+    c >= 1 as char && c <= 9 as char
+        || c == 11 as char
+        || c == 12 as char
+        || c >= 14 as char && c <= 127 as char
+}
+
+pub fn encode(s: &str) -> String {
+    if s.chars().all(allowed_char) {
+        s.into()
+    } else {
+        format!("=?utf-8?b?{}?=", base64::encode(s))
+    }
+}
+
+pub fn decode(s: &str) -> Option<String> {
+    let s = s.trim();
+    if s.starts_with("=?utf-8?b?") && s.ends_with("?=") {
+        let s = s.split_at(10).1;
+        let s = s.split_at(s.len() - 2).0;
+        base64::decode(s)
+            .map_err(|_| ())
+            .and_then(|v| {
+                if let Ok(s) = from_utf8(&v) {
+                    Ok(Some(s.into()))
+                } else {
+                    Err(())
+                }
+            })
+            .unwrap_or(None)
+    } else {
+        Some(s.into())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::{decode, encode};
+
+    #[test]
+    fn encode_ascii() {
+        assert_eq!(&encode("Kayo. ?"), "Kayo. ?");
+    }
+
+    #[test]
+    fn decode_ascii() {
+        assert_eq!(decode("Kayo. ?"), Some("Kayo. ?".into()));
+    }
+
+    #[test]
+    fn encode_utf8() {
+        assert_eq!(
+            &encode("Привет, мир!"),
+            "=?utf-8?b?0J/RgNC40LLQtdGCLCDQvNC40YAh?="
+        );
+    }
+
+    #[test]
+    fn decode_utf8() {
+        assert_eq!(
+            decode("=?utf-8?b?0J/RgNC40LLQtdGCLCDQvNC40YAh?="),
+            Some("Привет, мир!".into())
+        );
+    }
+}

src/response.rs

@@ -1,345 +0,0 @@
-// Copyright 2014 Alexis Mousset. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! SMTP response, containing a mandatory return code, and an optional text message
-
-use std::str::FromStr;
-use std::fmt::{Display, Formatter, Result};
-use std::result::Result as RResult;
-
-use self::Severity::*;
-use self::Category::*;
-
-/// First digit indicates severity
-#[derive(PartialEq,Eq,Copy,Clone,Debug)]
-pub enum Severity {
-    /// 2yx
-    PositiveCompletion,
-    /// 3yz
-    PositiveIntermediate,
-    /// 4yz
-    TransientNegativeCompletion,
-    /// 5yz
-    PermanentNegativeCompletion,
-}
-
-impl FromStr for Severity {
-    type Err = &'static str;
-    fn from_str(s: &str) -> RResult<Severity, &'static str> {
-        match s {
-            "2" => Ok(PositiveCompletion),
-            "3" => Ok(PositiveIntermediate),
-            "4" => Ok(TransientNegativeCompletion),
-            "5" => Ok(PermanentNegativeCompletion),
-            _ => Err("First digit must be between 2 and 5"),
-        }
-    }
-}
-
-impl Display for Severity {
-    fn fmt(&self, f: &mut Formatter) -> Result {
-        write!(f, "{}",
-            match *self {
-                PositiveCompletion => 2,
-                PositiveIntermediate => 3,
-                TransientNegativeCompletion => 4,
-                PermanentNegativeCompletion => 5,
-            }
-        )
-    }
-}
-
-/// Second digit
-#[derive(PartialEq,Eq,Copy,Clone,Debug)]
-pub enum Category {
-    /// x0z
-    Syntax,
-    /// x1z
-    Information,
-    /// x2z
-    Connections,
-    /// x3z
-    Unspecified3,
-    /// x4z
-    Unspecified4,
-    /// x5z
-    MailSystem,
-}
-
-impl FromStr for Category {
-    type Err = &'static str;
-    fn from_str(s: &str) -> RResult<Category, &'static str> {
-        match s {
-            "0" => Ok(Syntax),
-            "1" => Ok(Information),
-            "2" => Ok(Connections),
-            "3" => Ok(Unspecified3),
-            "4" => Ok(Unspecified4),
-            "5" => Ok(MailSystem),
-            _ => Err("Second digit must be between 0 and 5"),
-        }
-    }
-}
-
-impl Display for Category {
-    fn fmt(&self, f: &mut Formatter) -> Result {
-        write!(f, "{}",
-            match *self {
-                Syntax => 0,
-                Information => 1,
-                Connections => 2,
-                Unspecified3 => 3,
-                Unspecified4 => 4,
-                MailSystem => 5,
-            }
-        )
-    }
-}
-
-/// Contains an SMTP reply, with separed code and message
-///
-/// The text message is optional, only the code is mandatory
-#[derive(PartialEq,Eq,Clone,Debug)]
-pub struct Response {
-    /// First digit of the response code
-    severity: Severity,
-    /// Second digit of the response code
-    category: Category,
-    /// Third digit
-    detail: u8,
-    /// Server response string (optional)
-    /// Handle multiline responses
-    message: Vec<String>
-}
-
-impl Response {
-    /// Creates a new `Response`
-    pub fn new(severity: Severity, category: Category, detail: u8, message: Vec<String>) -> Response {
-        Response {
-            severity: severity,
-            category: category,
-            detail: detail,
-            message: message
-        }
-    }
-
-    /// Tells if the response is positive
-    pub fn is_positive(&self) -> bool {
-        match self.severity {
-            PositiveCompletion => true,
-            PositiveIntermediate => true,
-            _ => false,
-        }
-    }
-
-    /// Returns the message
-    pub fn message(&self) -> Vec<String> {
-        self.message.clone()
-    }
-
-    /// Returns the severity (i.e. 1st digit)
-    pub fn severity(&self) -> Severity {
-        self.severity
-    }
-
-    /// Returns the category (i.e. 2nd digit)
-    pub fn category(&self) -> Category {
-        self.category
-    }
-
-    /// Returns the detail (i.e. 3rd digit)
-    pub fn detail(&self) -> u8 {
-        self.detail
-    }
-
-    /// Returns the reply code
-    fn code(&self) -> String {
-        format!("{}{}{}", self.severity, self.category, self.detail)
-    }
-
-    /// Checls code equality
-    pub fn has_code(&self, code: u16) -> bool {
-        self.code() == format!("{}", code)
-    }
-
-    /// Returns only the first word of the message if possible
-    pub fn first_word(&self) -> Option<String> {
-        match self.message.is_empty() {
-            true => None,
-            false => Some(self.message[0].split(" ").next().unwrap().to_string()),
-        }
-
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::{Severity, Category, Response};
-
-    #[test]
-    fn test_severity_from_str() {
-        assert_eq!("2".parse::<Severity>(), Ok(Severity::PositiveCompletion));
-        assert_eq!("4".parse::<Severity>(), Ok(Severity::TransientNegativeCompletion));
-        assert!("1".parse::<Severity>().is_err());
-    }
-
-    #[test]
-    fn test_severity_fmt() {
-        assert_eq!(format!("{}", Severity::PositiveCompletion), "2");
-    }
-
-    #[test]
-    fn test_category_from_str() {
-        assert_eq!("2".parse::<Category>(), Ok(Category::Connections));
-        assert_eq!("4".parse::<Category>(), Ok(Category::Unspecified4));
-        assert!("6".parse::<Category>().is_err());
-    }
-
-    #[test]
-    fn test_category_fmt() {
-        assert_eq!(format!("{}", Category::Unspecified4), "4");
-    }
-
-    #[test]
-    fn test_response_new() {
-        assert_eq!(Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]
-        ), Response {
-            severity: Severity::PositiveCompletion,
-            category: Category::Unspecified4,
-            detail: 1,
-            message: vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()],
-        });
-        assert_eq!(Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec![]
-        ), Response {
-            severity: Severity::PositiveCompletion,
-            category: Category::Unspecified4,
-            detail: 1,
-            message: vec![],
-        });
-    }
-
-    #[test]
-    fn test_response_is_positive() {
-        assert!(Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]
-        ).is_positive());
-        assert!(! Response::new(
-            "4".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]
-        ).is_positive());
-    }
-
-    #[test]
-    fn test_response_message() {
-        assert_eq!(Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]
-        ).message(), vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]);
-        let empty_message: Vec<String> = vec![];
-        assert_eq!(Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec![]
-        ).message(), empty_message);
-    }
-
-    #[test]
-    fn test_response_severity() {
-        assert_eq!(Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]
-        ).severity(), Severity::PositiveCompletion);
-    }
-
-    #[test]
-    fn test_response_category() {
-        assert_eq!(Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]
-        ).category(), Category::Unspecified4);
-    }
-
-    #[test]
-    fn test_response_detail() {
-        assert_eq!(Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]
-        ).detail(), 1);
-    }
-
-    #[test]
-    fn test_response_code() {
-        assert_eq!(Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]
-        ).code(), "241");
-    }
-
-    #[test]
-    fn test_response_has_code() {
-        assert!(Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]
-        ).has_code(241));
-        assert!(! Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]
-        ).has_code(251));
-    }
-
-    #[test]
-    fn test_response_first_word() {
-        assert_eq!(Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec!["me".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]
-        ).first_word(), Some("me".to_string()));
-        assert_eq!(Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec!["me mo".to_string(), "8BITMIME".to_string(), "SIZE 42".to_string()]
-        ).first_word(), Some("me".to_string()));
-        assert_eq!(Response::new(
-            "2".parse::<Severity>().unwrap(),
-            "4".parse::<Category>().unwrap(),
-            1,
-            vec![]
-        ).first_word(), None);
-    }
-}

src/sendable_email.rs

@@ -1,63 +0,0 @@
-// Copyright 2014 Alexis Mousset. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! SMTP sendable email
-
-use uuid::Uuid;
-
-/// Email sendable by an SMTP client
-pub trait SendableEmail {
-    /// From address
-    fn from_address(&self) -> String;
-    /// To addresses
-    fn to_addresses(&self) -> Vec<String>;
-    /// Message content
-    fn message(&self) -> String;
-    /// Message ID
-    fn message_id(&self) -> String;
-}
-
-/// Minimal email structure
-pub struct SimpleSendableEmail {
-    /// From address
-    from: String,
-    /// To addresses
-    to: Vec<String>,
-    /// Message
-    message: String,
-}
-
-impl SimpleSendableEmail {
-    /// Returns a new email
-    pub fn new(from_address: &str, to_address: &str, message: &str) -> SimpleSendableEmail {
-        SimpleSendableEmail {
-            from: from_address.to_string(),
-            to: vec![to_address.to_string()],
-            message: message.to_string(),
-        }
-    }
-}
-
-impl SendableEmail for SimpleSendableEmail {
-    fn from_address(&self) -> String {
-        self.from.clone()
-    }
-
-    fn to_addresses(&self) -> Vec<String> {
-        self.to.clone()
-    }
-
-    fn message(&self) -> String {
-        self.message.clone()
-    }
-
-    fn message_id(&self) -> String {
-        format!("<{}@rust-smtp>", Uuid::new_v4())
-    }
-}

src/sender/mod.rs

@@ -1,272 +0,0 @@
-// Copyright 2014 Alexis Mousset. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! Sends an email using the client
-
-use std::string::String;
-use std::net::{SocketAddr, ToSocketAddrs};
-
-use SMTP_PORT;
-use extension::Extension;
-use error::{SmtpResult, SmtpError};
-use sendable_email::SendableEmail;
-use sender::server_info::ServerInfo;
-use client::Client;
-use client::net::SmtpStream;
-
-mod server_info;
-
-/// Contains client configuration
-pub struct SenderBuilder {
-    /// Maximum connection reuse
-    ///
-    /// Zero means no limitation
-    connection_reuse_count_limit: u16,
-    /// Enable connection reuse
-    enable_connection_reuse: bool,
-    /// Name sent during HELO or EHLO
-    hello_name: String,
-    /// Credentials
-    credentials: Option<(String, String)>,
-    /// Socket we are connecting to
-    server_addr: SocketAddr,
-}
-
-/// Builder for the SMTP Sender
-impl SenderBuilder {
-    /// Creates a new local SMTP client
-    pub fn new<A: ToSocketAddrs>(addr: A) -> SenderBuilder {
-        SenderBuilder {
-            server_addr: addr.to_socket_addrs().ok().expect("could not parse server address").next().unwrap(),
-            credentials: None,
-            connection_reuse_count_limit: 100,
-            enable_connection_reuse: false,
-            hello_name: "localhost".to_string(),
-        }
-    }
-
-    /// Creates a new local SMTP client to port 25
-    pub fn localhost() -> SenderBuilder {
-        SenderBuilder::new(("localhost", SMTP_PORT))
-    }
-
-    /// Set the name used during HELO or EHLO
-    pub fn hello_name(mut self, name: &str) -> SenderBuilder {
-        self.hello_name = name.to_string();
-        self
-    }
-
-    /// Enable connection reuse
-    pub fn enable_connection_reuse(mut self, enable: bool) -> SenderBuilder {
-        self.enable_connection_reuse = enable;
-        self
-    }
-
-    /// Set the maximum number of emails sent using one connection
-    pub fn connection_reuse_count_limit(mut self, limit: u16) -> SenderBuilder {
-        self.connection_reuse_count_limit = limit;
-        self
-    }
-
-    /// Set the client credentials
-    pub fn credentials(mut self, username: &str, password: &str) -> SenderBuilder {
-        self.credentials = Some((username.to_string(), password.to_string()));
-        self
-    }
-
-    /// Build the SMTP client
-    ///
-    /// It does not connects to the server, but only creates the `Sender`
-    pub fn build(self) -> Sender {
-        Sender::new(self)
-    }
-}
-
-/// Represents the state of a client
-#[derive(Debug)]
-struct State {
-    /// Panic state
-    pub panic: bool,
-    /// Connection reuse counter
-    pub connection_reuse_count: u16,
-}
-
-/// Structure that implements the high level SMTP client
-pub struct Sender {
-    /// Information about the server
-    /// Value is None before HELO/EHLO
-    server_info: Option<ServerInfo>,
-    /// Sender variable states
-    state: State,
-    /// Information about the client
-    client_info: SenderBuilder,
-    /// Low level client
-    client: Client<SmtpStream>,
-}
-
-macro_rules! try_smtp (
-    ($err: expr, $client: ident) => ({
-        match $err {
-            Ok(val) => val,
-            Err(err) => {
-                if !$client.state.panic {
-                    $client.state.panic = true;
-                    $client.reset();
-                }
-                return Err(err)
-            },
-        }
-    })
-);
-
-impl Sender {
-    /// Creates a new SMTP client
-    ///
-    /// It does not connects to the server, but only creates the `Sender`
-    pub fn new(builder: SenderBuilder) -> Sender {
-        let client: Client<SmtpStream> = Client::new(builder.server_addr);
-        Sender{
-            client: client,
-            server_info: None,
-            client_info: builder,
-            state: State {
-                panic: false,
-                connection_reuse_count: 0,
-            },
-        }
-    }
-
-    /// Reset the client state
-    fn reset(&mut self) {
-        // Close the SMTP transaction if needed
-        self.close();
-
-        // Reset the client state
-        self.server_info = None;
-        self.state.panic = false;
-        self.state.connection_reuse_count = 0;
-    }
-
-    /// Closes the inner connection
-    pub fn close(&mut self) {
-        self.client.close();
-    }
-
-    /// Sends an email
-    pub fn send<T: SendableEmail>(&mut self, email: T) -> SmtpResult {
-        // Check if the connection is still available
-        if self.state.connection_reuse_count > 0 {
-            if !self.client.is_connected() {
-                self.reset();
-            }
-        }
-
-        // If there is a usable connection, test if the server answers and hello has been sent
-        if self.state.connection_reuse_count == 0 {
-            try!(self.client.connect());
-
-            // Log the connection
-            info!("connection established to {}", self.client_info.server_addr);
-
-            // Extended Hello or Hello if needed
-            match self.client.ehlo(&self.client_info.hello_name) {
-                Ok(response) => {self.server_info = Some(
-                    ServerInfo{
-                        name: response.first_word().expect("Server announced no hostname"),
-                        esmtp_features: Extension::parse_esmtp_response(&response),
-                    });
-                },
-                Err(error) => match error {
-                    SmtpError::PermanentError(ref response) if response.has_code(550) => {
-                        match self.client.helo(&self.client_info.hello_name) {
-                            Ok(response) => {self.server_info = Some(
-                                ServerInfo{
-                                    name: response.first_word().expect("Server announced no hostname"),
-                                    esmtp_features: vec!(),
-                                });
-                            },
-                            Err(error) => try_smtp!(Err(error), self)
-                        }
-
-                    },
-                    _ => {
-                        try_smtp!(Err(error), self)
-                    },
-                },
-            }
-
-            // Print server information
-            debug!("server {}", self.server_info.as_ref().unwrap());
-        }
-
-        // TODO: Use PLAIN AUTH in encrypted connections, CRAM-MD5 otherwise
-        if self.client_info.credentials.is_some() && self.state.connection_reuse_count == 0 {
-
-            let (username, password) = self.client_info.credentials.clone().unwrap();
-
-            if self.server_info.as_ref().unwrap().supports_feature(Extension::CramMd5Authentication) {
-                let result = self.client.auth_cram_md5(&username, &password);
-                try_smtp!(result, self);
-            } else if self.server_info.as_ref().unwrap().supports_feature(Extension::PlainAuthentication) {
-                let result = self.client.auth_plain(&username, &password);
-                try_smtp!(result, self);
-            } else {
-                debug!("No supported authentication mecanisms available");
-            }
-        }
-
-        let current_message = email.message_id();
-        let from_address = email.from_address();
-        let to_addresses = email.to_addresses();
-        let message = email.message();
-
-        // Mail
-        let mail_options = match self.server_info.as_ref().unwrap().supports_feature(Extension::EightBitMime) {
-            true => Some("BODY=8BITMIME"),
-            false => None,
-        };
-
-        try_smtp!(self.client.mail(&from_address, mail_options), self);
-
-        // Log the mail command
-        info!("{}: from=<{}>", current_message, from_address);
-
-        // Recipient
-        for to_address in to_addresses.iter() {
-            try_smtp!(self.client.rcpt(&to_address), self);
-            // Log the rcpt command
-            info!("{}: to=<{}>", current_message, to_address);
-        }
-
-        // Data
-        try_smtp!(self.client.data(), self);
-
-        // Message content
-        let result = self.client.message(&message);
-
-        if result.is_ok() {
-            // Increment the connection reuse counter
-            self.state.connection_reuse_count = self.state.connection_reuse_count + 1;
-
-            // Log the message
-            info!("{}: conn_use={}, size={}, status=sent ({})", current_message,
-                self.state.connection_reuse_count, message.len(),
-                result.as_ref().ok().unwrap().message().iter().next().unwrap_or(&"no response".to_string())
-            );
-        }
-
-        // Test if we can reuse the existing connection
-        if (!self.client_info.enable_connection_reuse) ||
-            (self.state.connection_reuse_count >= self.client_info.connection_reuse_count_limit) {
-            self.reset();
-        }
-
-        result
-    }
-}

src/sender/server_info.rs

@@ -1,85 +0,0 @@
-// Copyright 2014 Alexis Mousset. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! Information about a server
-
-use std::fmt;
-use std::fmt::{Display, Formatter};
-
-use extension::Extension;
-
-/// Contains information about an SMTP server
-#[derive(Clone,Debug)]
-pub struct ServerInfo {
-    /// Server name
-    ///
-    /// The name given in the server banner
-    pub name: String,
-    /// ESMTP features supported by the server
-    ///
-    /// It contains the features supported by the server and known by the `Extension` module.
-    pub esmtp_features: Vec<Extension>,
-}
-
-impl Display for ServerInfo {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        write!(f, "{} with {}",
-            self.name,
-            match self.esmtp_features.is_empty() {
-                true => "no supported features".to_string(),
-                false => format! ("{:?}", self.esmtp_features),
-            }
-        )
-    }
-}
-
-impl ServerInfo {
-    /// Checks if the server supports an ESMTP feature
-    pub fn supports_feature(&self, keyword: Extension) -> bool {
-        self.esmtp_features.contains(&keyword)
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::ServerInfo;
-    use extension::Extension;
-
-    #[test]
-    fn test_fmt() {
-        assert_eq!(format!("{}", ServerInfo{
-            name: "name".to_string(),
-            esmtp_features: vec![Extension::EightBitMime]
-        }), "name with [EightBitMime]".to_string());
-        assert_eq!(format!("{}", ServerInfo{
-            name: "name".to_string(),
-            esmtp_features: vec![Extension::EightBitMime]
-        }), "name with [EightBitMime]".to_string());
-        assert_eq!(format!("{}", ServerInfo{
-            name: "name".to_string(),
-            esmtp_features: vec![]
-        }), "name with no supported features".to_string());
-    }
-
-    #[test]
-    fn test_supports_feature() {
-        assert!(ServerInfo{
-            name: "name".to_string(),
-            esmtp_features: vec![Extension::EightBitMime]
-        }.supports_feature(Extension::EightBitMime));
-        assert!(ServerInfo{
-            name: "name".to_string(),
-            esmtp_features: vec![Extension::PlainAuthentication, Extension::EightBitMime]
-        }.supports_feature(Extension::EightBitMime));
-        assert_eq!(ServerInfo{
-            name: "name".to_string(),
-            esmtp_features: vec![Extension::EightBitMime]
-        }.supports_feature(Extension::PlainAuthentication), false);
-    }
-}

src/transport/file/error.rs

@@ -0,0 +1,57 @@
+//! Error and result type for file transport
+
+use self::Error::*;
+use std::{
+    error::Error as StdError,
+    fmt::{self, Display, Formatter},
+    io,
+};
+
+/// An enum of all error kinds.
+#[derive(Debug)]
+pub enum Error {
+    /// Internal client error
+    Client(&'static str),
+    /// IO error
+    Io(io::Error),
+    /// JSON serialization error
+    JsonSerialization(serde_json::Error),
+}
+
+impl Display for Error {
+    fn fmt(&self, fmt: &mut Formatter) -> Result<(), fmt::Error> {
+        match *self {
+            Client(err) => fmt.write_str(err),
+            Io(ref err) => err.fmt(fmt),
+            JsonSerialization(ref err) => err.fmt(fmt),
+        }
+    }
+}
+
+impl StdError for Error {
+    fn source(&self) -> Option<&(dyn StdError + 'static)> {
+        match *self {
+            Io(ref err) => Some(&*err),
+            JsonSerialization(ref err) => Some(&*err),
+            _ => None,
+        }
+    }
+}
+
+impl From<io::Error> for Error {
+    fn from(err: io::Error) -> Error {
+        Error::Io(err)
+    }
+}
+
+impl From<serde_json::Error> for Error {
+    fn from(err: serde_json::Error) -> Error {
+        Error::JsonSerialization(err)
+    }
+}
+
+impl From<&'static str> for Error {
+    fn from(string: &'static str) -> Error {
+        Error::Client(string)
+    }
+}

src/transport/file/mod.rs

@@ -0,0 +1,144 @@
+//! The file transport writes the emails to the given directory. The name of the file will be
+//! `message_id.txt`.
+//! It can be useful for testing purposes, or if you want to keep track of sent messages.
+//!
+//! #### File Transport
+//!
+//! The file transport writes the emails to the given directory. The name of the file will be
+//! `message_id.json`.
+//! It can be useful for testing purposes, or if you want to keep track of sent messages.
+//!
+//! ```rust
+//! # #[cfg(feature = "file-transport")]
+//! # {
+//! use std::env::temp_dir;
+//! use lettre::{Transport, Envelope, Message, FileTransport};
+//!
+//! // Write to the local temp directory
+//! let sender = FileTransport::new(temp_dir());
+//! let email = Message::builder()
+//!     .from("NoBody <nobody@domain.tld>".parse().unwrap())
+//!     .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+//!     .to("Hei <hei@domain.tld>".parse().unwrap())
+//!     .subject("Happy new year")
+//!     .body("Be happy!")
+//!     .unwrap();
+//!
+//! let result = sender.send(&email);
+//! assert!(result.is_ok());
+//! # }
+//! ```
+//!
+//! Example result in `/tmp/b7c211bc-9811-45ce-8cd9-68eab575d695.json`:
+//!
+//! ```json
+//! TODO
+//! ```
+
+use crate::{transport::file::error::Error, Envelope, Transport};
+use std::{
+    fs::File,
+    io::prelude::*,
+    path::{Path, PathBuf},
+    str,
+};
+use uuid::Uuid;
+
+pub mod error;
+
+type Id = String;
+
+/// Writes the content and the envelope information to a file
+#[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct FileTransport {
+    path: PathBuf,
+}
+
+impl FileTransport {
+    /// Creates a new transport to the given directory
+    pub fn new<P: AsRef<Path>>(path: P) -> FileTransport {
+        FileTransport {
+            path: PathBuf::from(path.as_ref()),
+        }
+    }
+}
+
+#[derive(PartialEq, Eq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+struct SerializableEmail<'a> {
+    envelope: Envelope,
+    raw_message: Option<&'a [u8]>,
+    message: Option<&'a str>,
+}
+
+impl Transport for FileTransport {
+    type Ok = Id;
+    type Error = Error;
+
+    fn send_raw(&self, envelope: &Envelope, email: &[u8]) -> Result<Self::Ok, Self::Error> {
+        let email_id = Uuid::new_v4();
+        let file = self.path.join(format!("{}.json", email_id));
+
+        let serialized = match str::from_utf8(email) {
+            // Serialize as UTF-8 string if possible
+            Ok(m) => serde_json::to_string(&SerializableEmail {
+                envelope: envelope.clone(),
+                message: Some(m),
+                raw_message: None,
+            }),
+            Err(_) => serde_json::to_string(&SerializableEmail {
+                envelope: envelope.clone(),
+                message: None,
+                raw_message: Some(email),
+            }),
+        }?;
+
+        File::create(file.as_path())?.write_all(serialized.as_bytes())?;
+        Ok(email_id.to_string())
+    }
+}
+
+#[cfg(feature = "async")]
+pub mod r#async {
+    use super::{FileTransport, Id, SerializableEmail};
+    use crate::{r#async::Transport, transport::file::error::Error, Envelope};
+    use async_std::fs::File;
+    use async_std::prelude::*;
+    use async_trait::async_trait;
+    use std::str;
+    use uuid::Uuid;
+
+    #[async_trait]
+    impl Transport for FileTransport {
+        type Ok = Id;
+        type Error = Error;
+
+        async fn send_raw(
+            &self,
+            envelope: &Envelope,
+            email: &[u8],
+        ) -> Result<Self::Ok, Self::Error> {
+            let email_id = Uuid::new_v4();
+            let file = self.path.join(format!("{}.json", email_id));
+
+            let serialized = match str::from_utf8(email) {
+                // Serialize as UTF-8 string if possible
+                Ok(m) => serde_json::to_string(&SerializableEmail {
+                    envelope: envelope.clone(),
+                    message: Some(m),
+                    raw_message: None,
+                }),
+                Err(_) => serde_json::to_string(&SerializableEmail {
+                    envelope: envelope.clone(),
+                    message: None,
+                    raw_message: Some(email),
+                }),
+            }?;
+
+            let mut file = File::create(file.as_path()).await?;
+            file.write_all(serialized.as_bytes()).await?;
+            Ok(email_id.to_string())
+        }
+    }
+}

src/transport/mod.rs

@@ -0,0 +1,25 @@
+//! ### Sending Messages
+//!
+//! This section explains how to manipulate emails you have created.
+//!
+//! This mailer contains several different transports for your emails. To be sendable, the
+//! emails have to implement `Email`, which is the case for emails created with `lettre::builder`.
+//!
+//! The following transports are available:
+//!
+//! * The `SmtpTransport` uses the SMTP protocol to send the message over the network. It is
+//!   the preferred way of sending emails.
+//! * The `SendmailTransport` uses the sendmail command to send messages. It is an alternative to
+//!   the SMTP transport.
+//! * The `FileTransport` creates a file containing the email content to be sent. It can be used
+//!   for debugging or if you want to keep all sent emails.
+//! * The `StubTransport` is useful for debugging, and only prints the content of the email in the
+//!   logs.
+
+#[cfg(feature = "file-transport")]
+pub mod file;
+#[cfg(feature = "sendmail-transport")]
+pub mod sendmail;
+#[cfg(feature = "smtp-transport")]
+pub mod smtp;
+pub mod stub;

src/transport/sendmail/error.rs

@@ -0,0 +1,52 @@
+//! Error and result type for sendmail transport
+
+use self::Error::*;
+use std::{
+    error::Error as StdError,
+    fmt::{self, Display, Formatter},
+    io,
+    string::FromUtf8Error,
+};
+
+/// An enum of all error kinds.
+#[derive(Debug)]
+pub enum Error {
+    /// Internal client error
+    Client(String),
+    /// Error parsing UTF8 in response
+    Utf8Parsing(FromUtf8Error),
+    /// IO error
+    Io(io::Error),
+}
+
+impl Display for Error {
+    fn fmt(&self, fmt: &mut Formatter) -> Result<(), fmt::Error> {
+        match *self {
+            Client(ref err) => err.fmt(fmt),
+            Utf8Parsing(ref err) => err.fmt(fmt),
+            Io(ref err) => err.fmt(fmt),
+        }
+    }
+}
+
+impl StdError for Error {
+    fn source(&self) -> Option<&(dyn StdError + 'static)> {
+        match *self {
+            Io(ref err) => Some(&*err),
+            Utf8Parsing(ref err) => Some(&*err),
+            _ => None,
+        }
+    }
+}
+
+impl From<io::Error> for Error {
+    fn from(err: io::Error) -> Error {
+        Error::Io(err)
+    }
+}
+
+impl From<FromUtf8Error> for Error {
+    fn from(err: FromUtf8Error) -> Error {
+        Utf8Parsing(err)
+    }
+}

src/transport/sendmail/mod.rs

@@ -0,0 +1,128 @@
+//! The sendmail transport sends the email using the local sendmail command.
+//!
+//! #### Sendmail Transport
+//!
+//! The sendmail transport sends the email using the local sendmail command.
+//!
+//! ```rust,no_run
+//! # #[cfg(feature = "sendmail-transport")]
+//! # {
+//! use lettre::{Message, Envelope, Transport, SendmailTransport};
+//!
+//! let email = Message::builder()
+//!     .from("NoBody <nobody@domain.tld>".parse().unwrap())
+//!     .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+//!     .to("Hei <hei@domain.tld>".parse().unwrap())
+//!     .subject("Happy new year")
+//!     .body("Be happy!")
+//!     .unwrap();
+//!
+//! let sender = SendmailTransport::new();
+//! let result = sender.send(&email);
+//! assert!(result.is_ok());
+//! # }
+//! ```
+
+use crate::{transport::sendmail::error::Error, Envelope, Transport};
+use std::{
+    convert::AsRef,
+    ffi::OsString,
+    io::prelude::*,
+    process::{Command, Stdio},
+};
+
+pub mod error;
+
+const DEFAUT_SENDMAIL: &str = "/usr/sbin/sendmail";
+
+/// Sends an email using the `sendmail` command
+#[derive(Debug, Default)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct SendmailTransport {
+    command: OsString,
+}
+
+impl SendmailTransport {
+    /// Creates a new transport with the default `/usr/sbin/sendmail` command
+    pub fn new() -> SendmailTransport {
+        SendmailTransport {
+            command: DEFAUT_SENDMAIL.into(),
+        }
+    }
+
+    /// Creates a new transport to the given sendmail command
+    pub fn new_with_command<S: Into<OsString>>(command: S) -> SendmailTransport {
+        SendmailTransport {
+            command: command.into(),
+        }
+    }
+
+    fn command(&self, envelope: &Envelope) -> Command {
+        let mut c = Command::new(&self.command);
+        c.arg("-i")
+            .arg("-f")
+            .arg(envelope.from().map(|f| f.as_ref()).unwrap_or("\"\""))
+            .args(envelope.to())
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped());
+        c
+    }
+}
+
+impl Transport for SendmailTransport {
+    type Ok = ();
+    type Error = Error;
+
+    fn send_raw(&self, envelope: &Envelope, email: &[u8]) -> Result<Self::Ok, Self::Error> {
+        // Spawn the sendmail command
+        let mut process = self.command(envelope).spawn()?;
+
+        process.stdin.as_mut().unwrap().write_all(email)?;
+        let output = process.wait_with_output()?;
+
+        if output.status.success() {
+            Ok(())
+        } else {
+            Err(error::Error::Client(String::from_utf8(output.stderr)?))
+        }
+    }
+}
+
+#[cfg(feature = "async")]
+pub mod r#async {
+    use super::SendmailTransport;
+    use crate::{r#async::Transport, transport::sendmail::error::Error, Envelope};
+    use async_trait::async_trait;
+    use std::io::Write;
+
+    #[async_trait]
+    impl Transport for SendmailTransport {
+        type Ok = ();
+        type Error = Error;
+
+        // TODO: Convert to real async, once async-std has a process implementation.
+        async fn send_raw(
+            &self,
+            envelope: &Envelope,
+            email: &[u8],
+        ) -> Result<Self::Ok, Self::Error> {
+            let mut command = self.command(envelope);
+            let email = email.to_vec();
+
+            let output = async_std::task::spawn_blocking(move || {
+                // Spawn the sendmail command
+                let mut process = command.spawn()?;
+
+                process.stdin.as_mut().unwrap().write_all(&email)?;
+                process.wait_with_output()
+            })
+            .await?;
+
+            if output.status.success() {
+                Ok(())
+            } else {
+                Err(Error::Client(String::from_utf8(output.stderr)?))
+            }
+        }
+    }
+}

src/transport/smtp/authentication.rs

@@ -0,0 +1,175 @@
+//! Provides limited SASL authentication mechanisms
+
+use crate::transport::smtp::error::Error;
+use std::fmt::{self, Display, Formatter};
+
+/// Accepted authentication mechanisms
+/// Trying LOGIN last as it is deprecated.
+pub const DEFAULT_MECHANISMS: &[Mechanism] = &[Mechanism::Plain, Mechanism::Login];
+
+/// Convertible to user credentials
+pub trait IntoCredentials {
+    /// Converts to a `Credentials` struct
+    fn into_credentials(self) -> Credentials;
+}
+
+impl IntoCredentials for Credentials {
+    fn into_credentials(self) -> Credentials {
+        self
+    }
+}
+
+impl<S: Into<String>, T: Into<String>> IntoCredentials for (S, T) {
+    fn into_credentials(self) -> Credentials {
+        let (username, password) = self;
+        Credentials::new(username.into(), password.into())
+    }
+}
+
+/// Contains user credentials
+#[derive(PartialEq, Eq, Clone, Hash, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Credentials {
+    authentication_identity: String,
+    secret: String,
+}
+
+impl Credentials {
+    /// Create a `Credentials` struct from username and password
+    pub fn new(username: String, password: String) -> Credentials {
+        Credentials {
+            authentication_identity: username,
+            secret: password,
+        }
+    }
+}
+
+/// Represents authentication mechanisms
+#[derive(PartialEq, Eq, Copy, Clone, Hash, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub enum Mechanism {
+    /// PLAIN authentication mechanism
+    /// RFC 4616: https://tools.ietf.org/html/rfc4616
+    Plain,
+    /// LOGIN authentication mechanism
+    /// Obsolete but needed for some providers (like office365)
+    /// https://www.ietf.org/archive/id/draft-murchison-sasl-login-00.txt
+    Login,
+    /// Non-standard XOAUTH2 mechanism
+    /// https://developers.google.com/gmail/imap/xoauth2-protocol
+    Xoauth2,
+}
+
+impl Display for Mechanism {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(
+            f,
+            "{}",
+            match *self {
+                Mechanism::Plain => "PLAIN",
+                Mechanism::Login => "LOGIN",
+                Mechanism::Xoauth2 => "XOAUTH2",
+            }
+        )
+    }
+}
+
+impl Mechanism {
+    /// Does the mechanism supports initial response
+    pub fn supports_initial_response(self) -> bool {
+        match self {
+            Mechanism::Plain | Mechanism::Xoauth2 => true,
+            Mechanism::Login => false,
+        }
+    }
+
+    /// Returns the string to send to the server, using the provided username, password and
+    /// challenge in some cases
+    pub fn response(
+        self,
+        credentials: &Credentials,
+        challenge: Option<&str>,
+    ) -> Result<String, Error> {
+        match self {
+            Mechanism::Plain => match challenge {
+                Some(_) => Err(Error::Client("This mechanism does not expect a challenge")),
+                None => Ok(format!(
+                    "\u{0}{}\u{0}{}",
+                    credentials.authentication_identity, credentials.secret
+                )),
+            },
+            Mechanism::Login => {
+                let decoded_challenge =
+                    challenge.ok_or(Error::Client("This mechanism does expect a challenge"))?;
+
+                if vec!["User Name", "Username:", "Username"].contains(&decoded_challenge) {
+                    return Ok(credentials.authentication_identity.to_string());
+                }
+
+                if vec!["Password", "Password:"].contains(&decoded_challenge) {
+                    return Ok(credentials.secret.to_string());
+                }
+
+                Err(Error::Client("Unrecognized challenge"))
+            }
+            Mechanism::Xoauth2 => match challenge {
+                Some(_) => Err(Error::Client("This mechanism does not expect a challenge")),
+                None => Ok(format!(
+                    "user={}\x01auth=Bearer {}\x01\x01",
+                    credentials.authentication_identity, credentials.secret
+                )),
+            },
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::{Credentials, Mechanism};
+
+    #[test]
+    fn test_plain() {
+        let mechanism = Mechanism::Plain;
+
+        let credentials = Credentials::new("username".to_string(), "password".to_string());
+
+        assert_eq!(
+            mechanism.response(&credentials, None).unwrap(),
+            "\u{0}username\u{0}password"
+        );
+        assert!(mechanism.response(&credentials, Some("test")).is_err());
+    }
+
+    #[test]
+    fn test_login() {
+        let mechanism = Mechanism::Login;
+
+        let credentials = Credentials::new("alice".to_string(), "wonderland".to_string());
+
+        assert_eq!(
+            mechanism.response(&credentials, Some("Username")).unwrap(),
+            "alice"
+        );
+        assert_eq!(
+            mechanism.response(&credentials, Some("Password")).unwrap(),
+            "wonderland"
+        );
+        assert!(mechanism.response(&credentials, None).is_err());
+    }
+
+    #[test]
+    fn test_xoauth2() {
+        let mechanism = Mechanism::Xoauth2;
+
+        let credentials = Credentials::new(
+            "username".to_string(),
+            "vF9dft4qmTc2Nvb3RlckBhdHRhdmlzdGEuY29tCg==".to_string(),
+        );
+
+        assert_eq!(
+            mechanism.response(&credentials, None).unwrap(),
+            "user=username\x01auth=Bearer vF9dft4qmTc2Nvb3RlckBhdHRhdmlzdGEuY29tCg==\x01\x01"
+        );
+        assert!(mechanism.response(&credentials, Some("test")).is_err());
+    }
+}

src/transport/smtp/client/mock.rs

@@ -0,0 +1,122 @@
+#![allow(missing_docs)]
+// Comes from https://github.com/inre/rust-mq/blob/master/netopt
+
+use std::{
+    io::{self, Cursor, Read, Write},
+    sync::{Arc, Mutex},
+};
+
+pub type MockCursor = Cursor<Vec<u8>>;
+
+#[derive(Clone, Debug)]
+pub struct MockStream {
+    reader: Arc<Mutex<MockCursor>>,
+    writer: Arc<Mutex<MockCursor>>,
+}
+
+impl Default for MockStream {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl MockStream {
+    pub fn new() -> MockStream {
+        MockStream {
+            reader: Arc::new(Mutex::new(MockCursor::new(Vec::new()))),
+            writer: Arc::new(Mutex::new(MockCursor::new(Vec::new()))),
+        }
+    }
+
+    pub fn with_vec(vec: Vec<u8>) -> MockStream {
+        MockStream {
+            reader: Arc::new(Mutex::new(MockCursor::new(vec))),
+            writer: Arc::new(Mutex::new(MockCursor::new(Vec::new()))),
+        }
+    }
+
+    pub fn take_vec(&mut self) -> Vec<u8> {
+        let mut cursor = self.writer.lock().unwrap();
+        let vec = cursor.get_ref().to_vec();
+        cursor.set_position(0);
+        cursor.get_mut().clear();
+        vec
+    }
+
+    pub fn next_vec(&mut self, vec: &[u8]) {
+        let mut cursor = self.reader.lock().unwrap();
+        cursor.set_position(0);
+        cursor.get_mut().clear();
+        cursor.get_mut().extend_from_slice(vec);
+    }
+
+    pub fn swap(&mut self) {
+        let mut cur_write = self.writer.lock().unwrap();
+        let mut cur_read = self.reader.lock().unwrap();
+        let vec_write = cur_write.get_ref().to_vec();
+        let vec_read = cur_read.get_ref().to_vec();
+        cur_write.set_position(0);
+        cur_read.set_position(0);
+        cur_write.get_mut().clear();
+        cur_read.get_mut().clear();
+        // swap cursors
+        cur_read.get_mut().extend_from_slice(vec_write.as_slice());
+        cur_write.get_mut().extend_from_slice(vec_read.as_slice());
+    }
+}
+
+impl Write for MockStream {
+    fn write(&mut self, msg: &[u8]) -> io::Result<usize> {
+        self.writer.lock().unwrap().write(msg)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        self.writer.lock().unwrap().flush()
+    }
+}
+
+impl Read for MockStream {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.reader.lock().unwrap().read(buf)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::MockStream;
+    use std::io::{Read, Write};
+
+    #[test]
+    fn write_take_test() {
+        let mut mock = MockStream::new();
+        // write to mock stream
+        mock.write_all(&[1, 2, 3]).unwrap();
+        assert_eq!(mock.take_vec(), vec![1, 2, 3]);
+    }
+
+    #[test]
+    fn read_with_vec_test() {
+        let mut mock = MockStream::with_vec(vec![4, 5]);
+        let mut vec = Vec::new();
+        mock.read_to_end(&mut vec).unwrap();
+        assert_eq!(vec, vec![4, 5]);
+    }
+
+    #[test]
+    fn clone_test() {
+        let mut mock = MockStream::new();
+        let mut cloned = mock.clone();
+        mock.write_all(&[6, 7]).unwrap();
+        assert_eq!(cloned.take_vec(), vec![6, 7]);
+    }
+
+    #[test]
+    fn swap_test() {
+        let mut mock = MockStream::new();
+        let mut vec = Vec::new();
+        mock.write_all(&[8, 9, 10]).unwrap();
+        mock.swap();
+        mock.read_to_end(&mut vec).unwrap();
+        assert_eq!(vec, vec![8, 9, 10]);
+    }
+}

src/transport/smtp/client/mod.rs

@@ -0,0 +1,376 @@
+//! SMTP client
+
+use crate::{
+    transport::smtp::{
+        authentication::{Credentials, Mechanism},
+        client::net::{NetworkStream, TlsParameters},
+        commands::*,
+        error::Error,
+        extension::{ClientId, Extension, MailBodyParameter, MailParameter, ServerInfo},
+        response::{parse_response, Response},
+    },
+    Envelope,
+};
+use bufstream::BufStream;
+#[cfg(feature = "log")]
+use log::debug;
+#[cfg(feature = "serde")]
+use std::fmt::Debug;
+use std::{
+    fmt::Display,
+    io::{self, BufRead, Write},
+    net::ToSocketAddrs,
+    string::String,
+    time::Duration,
+};
+
+pub mod mock;
+pub mod net;
+
+/// The codec used for transparency
+#[derive(Default, Clone, Copy, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct ClientCodec {
+    escape_count: u8,
+}
+
+impl ClientCodec {
+    /// Creates a new client codec
+    pub fn new() -> Self {
+        ClientCodec::default()
+    }
+
+    /// Adds transparency
+    fn encode(&mut self, frame: &[u8], buf: &mut Vec<u8>) -> Result<(), Error> {
+        match frame.len() {
+            0 => {
+                match self.escape_count {
+                    0 => buf.write_all(b"\r\n.\r\n")?,
+                    1 => buf.write_all(b"\n.\r\n")?,
+                    2 => buf.write_all(b".\r\n")?,
+                    _ => unreachable!(),
+                }
+                self.escape_count = 0;
+                Ok(())
+            }
+            _ => {
+                let mut start = 0;
+                for (idx, byte) in frame.iter().enumerate() {
+                    match self.escape_count {
+                        0 => self.escape_count = if *byte == b'\r' { 1 } else { 0 },
+                        1 => self.escape_count = if *byte == b'\n' { 2 } else { 0 },
+                        2 => self.escape_count = if *byte == b'.' { 3 } else { 0 },
+                        _ => unreachable!(),
+                    }
+                    if self.escape_count == 3 {
+                        self.escape_count = 0;
+                        buf.write_all(&frame[start..idx])?;
+                        buf.write_all(b".")?;
+                        start = idx;
+                    }
+                }
+                buf.write_all(&frame[start..])?;
+                Ok(())
+            }
+        }
+    }
+}
+
+/// Returns the string replacing all the CRLF with "\<CRLF\>"
+/// Used for debug displays
+#[cfg(feature = "log")]
+fn escape_crlf(string: &str) -> String {
+    string.replace("\r\n", "<CRLF>")
+}
+
+macro_rules! try_smtp (
+    ($err: expr, $client: ident) => ({
+        match $err {
+            Ok(val) => val,
+            Err(err) => {
+                $client.abort();
+                return Err(From::from(err))
+            },
+        }
+    })
+);
+
+/// Structure that implements the SMTP client
+pub struct SmtpConnection {
+    /// TCP stream between client and server
+    /// Value is None before connection
+    stream: BufStream<NetworkStream>,
+    /// Panic state
+    panic: bool,
+    /// Information about the server
+    server_info: ServerInfo,
+}
+
+impl SmtpConnection {
+    pub fn server_info(&self) -> &ServerInfo {
+        &self.server_info
+    }
+
+    // FIXME add simple connect and rename this one
+
+    /// Connects to the configured server
+    ///
+    /// Sends EHLO and parses server information
+    pub fn connect<A: ToSocketAddrs>(
+        server: A,
+        timeout: Option<Duration>,
+        hello_name: &ClientId,
+        tls_parameters: Option<&TlsParameters>,
+    ) -> Result<SmtpConnection, Error> {
+        let stream = BufStream::new(NetworkStream::connect(server, timeout, tls_parameters)?);
+        let mut conn = SmtpConnection {
+            stream,
+            panic: false,
+            server_info: ServerInfo::default(),
+        };
+        conn.set_timeout(timeout)?;
+        // TODO log
+        let _response = conn.read_response()?;
+
+        conn.ehlo(hello_name)?;
+
+        // Print server information
+        #[cfg(feature = "log")]
+        debug!("server {}", conn.server_info);
+        Ok(conn)
+    }
+
+    pub fn send(&mut self, envelope: &Envelope, email: &[u8]) -> Result<Response, Error> {
+        // Mail
+        let mut mail_options = vec![];
+
+        if self.server_info().supports_feature(Extension::EightBitMime) {
+            mail_options.push(MailParameter::Body(MailBodyParameter::EightBitMime));
+        }
+        try_smtp!(
+            self.command(Mail::new(envelope.from().cloned(), mail_options,)),
+            self
+        );
+
+        // Recipient
+        for to_address in envelope.to() {
+            try_smtp!(self.command(Rcpt::new(to_address.clone(), vec![])), self);
+        }
+
+        // Data
+        try_smtp!(self.command(Data), self);
+
+        // Message content
+        let result = try_smtp!(self.message(email), self);
+        Ok(result)
+    }
+
+    pub fn has_broken(&self) -> bool {
+        self.panic
+    }
+
+    pub fn can_starttls(&self) -> bool {
+        !self.stream.get_ref().is_encrypted()
+            && self.server_info.supports_feature(Extension::StartTls)
+    }
+
+    #[allow(unused_variables)]
+    pub fn starttls(
+        &mut self,
+        tls_parameters: &TlsParameters,
+        hello_name: &ClientId,
+    ) -> Result<(), Error> {
+        if self.server_info.supports_feature(Extension::StartTls) {
+            #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+            {
+                try_smtp!(self.command(Starttls), self);
+                try_smtp!(self.stream.get_mut().upgrade_tls(tls_parameters), self);
+                #[cfg(feature = "log")]
+                debug!("connection encrypted");
+                // Send EHLO again
+                try_smtp!(self.ehlo(hello_name), self);
+                Ok(())
+            }
+            #[cfg(not(any(feature = "native-tls", feature = "rustls-tls")))]
+            // This should never happen as `Tls` can only be created
+            // when a TLS library is enabled
+            unreachable!("TLS support required but not supported");
+        } else {
+            Err(Error::Client("STARTTLS is not supported on this server"))
+        }
+    }
+
+    /// Send EHLO and update server info
+    fn ehlo(&mut self, hello_name: &ClientId) -> Result<(), Error> {
+        let ehlo_response = try_smtp!(
+            self.command(Ehlo::new(ClientId::new(hello_name.to_string()))),
+            self
+        );
+        self.server_info = try_smtp!(ServerInfo::from_response(&ehlo_response), self);
+        Ok(())
+    }
+
+    pub fn quit(&mut self) -> Result<Response, Error> {
+        Ok(try_smtp!(self.command(Quit), self))
+    }
+
+    pub fn abort(&mut self) {
+        // Only try to quit if we are not already broken
+        if !self.panic {
+            self.panic = true;
+            let _ = self.command(Quit);
+        }
+    }
+
+    /// Sets the underlying stream
+    pub fn set_stream(&mut self, stream: NetworkStream) {
+        self.stream = BufStream::new(stream);
+    }
+
+    /// Tells if the underlying stream is currently encrypted
+    pub fn is_encrypted(&self) -> bool {
+        self.stream.get_ref().is_encrypted()
+    }
+
+    /// Set timeout
+    pub fn set_timeout(&mut self, duration: Option<Duration>) -> io::Result<()> {
+        self.stream.get_mut().set_read_timeout(duration)?;
+        self.stream.get_mut().set_write_timeout(duration)
+    }
+
+    /// Checks if the server is connected using the NOOP SMTP command
+    pub fn test_connected(&mut self) -> bool {
+        self.command(Noop).is_ok()
+    }
+
+    /// Sends an AUTH command with the given mechanism, and handles challenge if needed
+    pub fn auth(
+        &mut self,
+        mechanisms: &[Mechanism],
+        credentials: &Credentials,
+    ) -> Result<Response, Error> {
+        let mechanism = match self.server_info.get_auth_mechanism(mechanisms) {
+            Some(m) => m,
+            None => {
+                return Err(Error::Client(
+                    "No compatible authentication mechanism was found",
+                ))
+            }
+        };
+
+        // Limit challenges to avoid blocking
+        let mut challenges = 10;
+        let mut response = self.command(Auth::new(mechanism, credentials.clone(), None)?)?;
+
+        while challenges > 0 && response.has_code(334) {
+            challenges -= 1;
+            response = try_smtp!(
+                self.command(Auth::new_from_response(
+                    mechanism,
+                    credentials.clone(),
+                    &response,
+                )?),
+                self
+            );
+        }
+
+        if challenges == 0 {
+            Err(Error::ResponseParsing("Unexpected number of challenges"))
+        } else {
+            Ok(response)
+        }
+    }
+
+    /// Sends the message content
+    pub fn message(&mut self, message: &[u8]) -> Result<Response, Error> {
+        let mut out_buf: Vec<u8> = vec![];
+        let mut codec = ClientCodec::new();
+        codec.encode(message, &mut out_buf)?;
+        self.write(out_buf.as_slice())?;
+        self.write(b"\r\n.\r\n")?;
+        self.read_response()
+    }
+
+    /// Sends an SMTP command
+    pub fn command<C: Display>(&mut self, command: C) -> Result<Response, Error> {
+        self.write(command.to_string().as_bytes())?;
+        self.read_response()
+    }
+
+    /// Writes a string to the server
+    fn write(&mut self, string: &[u8]) -> Result<(), Error> {
+        self.stream.write_all(string)?;
+        self.stream.flush()?;
+
+        #[cfg(feature = "log")]
+        debug!(
+            "Wrote: {}",
+            escape_crlf(String::from_utf8_lossy(string).as_ref())
+        );
+        Ok(())
+    }
+
+    /// Gets the SMTP response
+    pub fn read_response(&mut self) -> Result<Response, Error> {
+        let mut buffer = String::with_capacity(100);
+
+        while self.stream.read_line(&mut buffer)? > 0 {
+            #[cfg(feature = "log")]
+            debug!("<< {}", escape_crlf(&buffer));
+            match parse_response(&buffer) {
+                Ok((_remaining, response)) => {
+                    if response.is_positive() {
+                        return Ok(response);
+                    }
+
+                    return Err(response.into());
+                }
+                Err(nom::Err::Failure(e)) => {
+                    return Err(Error::Parsing(e.1));
+                }
+                Err(nom::Err::Incomplete(_)) => { /* read more */ }
+                Err(nom::Err::Error(e)) => {
+                    return Err(Error::Parsing(e.1));
+                }
+            }
+        }
+
+        Err(io::Error::new(io::ErrorKind::Other, "incomplete").into())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_codec() {
+        let mut codec = ClientCodec::new();
+        let mut buf: Vec<u8> = vec![];
+
+        assert!(codec.encode(b"test\r\n", &mut buf).is_ok());
+        assert!(codec.encode(b".\r\n", &mut buf).is_ok());
+        assert!(codec.encode(b"\r\ntest", &mut buf).is_ok());
+        assert!(codec.encode(b"te\r\n.\r\nst", &mut buf).is_ok());
+        assert!(codec.encode(b"test", &mut buf).is_ok());
+        assert!(codec.encode(b"test.", &mut buf).is_ok());
+        assert!(codec.encode(b"test\n", &mut buf).is_ok());
+        assert!(codec.encode(b".test\n", &mut buf).is_ok());
+        assert!(codec.encode(b"test", &mut buf).is_ok());
+        assert_eq!(
+            String::from_utf8(buf).unwrap(),
+            "test\r\n..\r\n\r\ntestte\r\n..\r\nsttesttest.test\n.test\ntest"
+        );
+    }
+
+    #[test]
+    #[cfg(feature = "log")]
+    fn test_escape_crlf() {
+        assert_eq!(escape_crlf("\r\n"), "<CRLF>");
+        assert_eq!(escape_crlf("EHLO my_name\r\n"), "EHLO my_name<CRLF>");
+        assert_eq!(
+            escape_crlf("EHLO my_name\r\nSIZE 42\r\n"),
+            "EHLO my_name<CRLF>SIZE 42<CRLF>"
+        );
+    }
+}

src/transport/smtp/client/net.rs

@@ -0,0 +1,230 @@
+//! A trait to represent a stream
+
+use crate::transport::smtp::{client::mock::MockStream, error::Error};
+#[cfg(feature = "native-tls")]
+use native_tls::{TlsConnector, TlsStream};
+#[cfg(feature = "rustls-tls")]
+use rustls::{ClientConfig, ClientSession};
+#[cfg(feature = "native-tls")]
+use std::io::ErrorKind;
+#[cfg(feature = "rustls-tls")]
+use std::sync::Arc;
+use std::{
+    io::{self, Read, Write},
+    net::{Ipv4Addr, Shutdown, SocketAddr, SocketAddrV4, TcpStream, ToSocketAddrs},
+    time::Duration,
+};
+
+/// Parameters to use for secure clients
+#[derive(Clone)]
+#[allow(missing_debug_implementations)]
+pub struct TlsParameters {
+    /// A connector from `native-tls`
+    #[cfg(feature = "native-tls")]
+    connector: TlsConnector,
+    /// A client from `rustls`
+    #[cfg(feature = "rustls-tls")]
+    // TODO use the same in all transports of the client
+    connector: Box<ClientConfig>,
+    /// The domain name which is expected in the TLS certificate from the server
+    domain: String,
+}
+
+impl TlsParameters {
+    /// Creates a `TlsParameters`
+    #[cfg(feature = "native-tls")]
+    pub fn new(domain: String, connector: TlsConnector) -> Self {
+        Self { connector, domain }
+    }
+
+    /// Creates a `TlsParameters`
+    #[cfg(feature = "rustls-tls")]
+    pub fn new(domain: String, connector: ClientConfig) -> Self {
+        Self {
+            connector: Box::new(connector),
+            domain,
+        }
+    }
+}
+
+/// Represents the different types of underlying network streams
+pub enum NetworkStream {
+    /// Plain TCP stream
+    Tcp(TcpStream),
+    /// Encrypted TCP stream
+    #[cfg(feature = "native-tls")]
+    Tls(Box<TlsStream<TcpStream>>),
+    #[cfg(feature = "rustls-tls")]
+    Tls(Box<rustls::StreamOwned<ClientSession, TcpStream>>),
+    /// Mock stream
+    Mock(MockStream),
+}
+
+impl NetworkStream {
+    /// Returns peer's address
+    pub fn peer_addr(&self) -> io::Result<SocketAddr> {
+        match *self {
+            NetworkStream::Tcp(ref s) => s.peer_addr(),
+            #[cfg(feature = "native-tls")]
+            NetworkStream::Tls(ref s) => s.get_ref().peer_addr(),
+            #[cfg(feature = "rustls-tls")]
+            NetworkStream::Tls(ref s) => s.get_ref().peer_addr(),
+            NetworkStream::Mock(_) => Ok(SocketAddr::V4(SocketAddrV4::new(
+                Ipv4Addr::new(127, 0, 0, 1),
+                80,
+            ))),
+        }
+    }
+
+    /// Shutdowns the connection
+    pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
+        match *self {
+            NetworkStream::Tcp(ref s) => s.shutdown(how),
+            #[cfg(feature = "native-tls")]
+            NetworkStream::Tls(ref s) => s.get_ref().shutdown(how),
+            #[cfg(feature = "rustls-tls")]
+            NetworkStream::Tls(ref s) => s.get_ref().shutdown(how),
+            NetworkStream::Mock(_) => Ok(()),
+        }
+    }
+
+    pub fn connect<T: ToSocketAddrs>(
+        server: T,
+        timeout: Option<Duration>,
+        tls_parameters: Option<&TlsParameters>,
+    ) -> Result<NetworkStream, Error> {
+        fn try_connect_timeout<T: ToSocketAddrs>(
+            server: T,
+            timeout: Duration,
+        ) -> Result<TcpStream, Error> {
+            let addrs = server.to_socket_addrs()?;
+            for addr in addrs {
+                let result = TcpStream::connect_timeout(&addr, timeout);
+                if result.is_ok() {
+                    return result.map_err(|e| e.into());
+                }
+            }
+            Err(Error::Client("Could not connect"))
+        }
+
+        let tcp_stream = match timeout {
+            Some(t) => try_connect_timeout(server, t)?,
+            None => TcpStream::connect(server)?,
+        };
+
+        match tls_parameters {
+            #[cfg(feature = "native-tls")]
+            Some(context) => context
+                .connector
+                .connect(context.domain.as_ref(), tcp_stream)
+                .map(|tls| NetworkStream::Tls(Box::new(tls)))
+                .map_err(|e| Error::Io(io::Error::new(ErrorKind::Other, e))),
+            #[cfg(feature = "rustls-tls")]
+            Some(context) => {
+                let domain = webpki::DNSNameRef::try_from_ascii_str(&context.domain)?;
+
+                Ok(NetworkStream::Tls(Box::new(rustls::StreamOwned::new(
+                    ClientSession::new(&Arc::new(*context.connector.clone()), domain),
+                    tcp_stream,
+                ))))
+            }
+            #[cfg(not(any(feature = "native-tls", feature = "rustls-tls")))]
+            Some(_) => panic!("TLS configuration without support"),
+            None => Ok(NetworkStream::Tcp(tcp_stream)),
+        }
+    }
+
+    #[allow(unused_variables, unreachable_code)]
+    pub fn upgrade_tls(&mut self, tls_parameters: &TlsParameters) -> Result<(), Error> {
+        *self = match *self {
+            #[cfg(feature = "native-tls")]
+            NetworkStream::Tcp(ref mut stream) => match tls_parameters
+                .connector
+                .connect(tls_parameters.domain.as_ref(), stream.try_clone().unwrap())
+            {
+                Ok(tls_stream) => NetworkStream::Tls(Box::new(tls_stream)),
+                Err(err) => return Err(Error::Io(io::Error::new(ErrorKind::Other, err))),
+            },
+            #[cfg(feature = "rustls-tls")]
+            NetworkStream::Tcp(ref mut stream) => {
+                let domain = webpki::DNSNameRef::try_from_ascii_str(&tls_parameters.domain)?;
+
+                NetworkStream::Tls(Box::new(rustls::StreamOwned::new(
+                    ClientSession::new(&Arc::new(*tls_parameters.connector.clone()), domain),
+                    stream.try_clone().unwrap(),
+                )))
+            }
+            #[cfg(not(any(feature = "native-tls", feature = "rustls-tls")))]
+            NetworkStream::Tcp(_) => panic!("STARTTLS without TLS support"),
+            #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+            NetworkStream::Tls(_) => return Ok(()),
+            NetworkStream::Mock(_) => return Ok(()),
+        };
+
+        Ok(())
+    }
+
+    pub fn is_encrypted(&self) -> bool {
+        match *self {
+            NetworkStream::Tcp(_) | NetworkStream::Mock(_) => false,
+            #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+            NetworkStream::Tls(_) => true,
+        }
+    }
+
+    pub fn set_read_timeout(&mut self, duration: Option<Duration>) -> io::Result<()> {
+        match *self {
+            NetworkStream::Tcp(ref mut stream) => stream.set_read_timeout(duration),
+            #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+            NetworkStream::Tls(ref mut stream) => stream.get_ref().set_read_timeout(duration),
+            NetworkStream::Mock(_) => Ok(()),
+        }
+    }
+
+    /// Set write timeout for IO calls
+    pub fn set_write_timeout(&mut self, duration: Option<Duration>) -> io::Result<()> {
+        match *self {
+            NetworkStream::Tcp(ref mut stream) => stream.set_write_timeout(duration),
+            #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+            NetworkStream::Tls(ref mut stream) => stream.get_ref().set_write_timeout(duration),
+            NetworkStream::Mock(_) => Ok(()),
+        }
+    }
+}
+
+impl Read for NetworkStream {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        match *self {
+            NetworkStream::Tcp(ref mut s) => s.read(buf),
+            #[cfg(feature = "native-tls")]
+            NetworkStream::Tls(ref mut s) => s.read(buf),
+            #[cfg(feature = "rustls-tls")]
+            NetworkStream::Tls(ref mut s) => s.read(buf),
+            NetworkStream::Mock(ref mut s) => s.read(buf),
+        }
+    }
+}
+
+impl Write for NetworkStream {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        match *self {
+            NetworkStream::Tcp(ref mut s) => s.write(buf),
+            #[cfg(feature = "native-tls")]
+            NetworkStream::Tls(ref mut s) => s.write(buf),
+            #[cfg(feature = "rustls-tls")]
+            NetworkStream::Tls(ref mut s) => s.write(buf),
+            NetworkStream::Mock(ref mut s) => s.write(buf),
+        }
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        match *self {
+            NetworkStream::Tcp(ref mut s) => s.flush(),
+            #[cfg(feature = "native-tls")]
+            NetworkStream::Tls(ref mut s) => s.flush(),
+            #[cfg(feature = "rustls-tls")]
+            NetworkStream::Tls(ref mut s) => s.flush(),
+            NetworkStream::Mock(ref mut s) => s.flush(),
+        }
+    }
+}

src/transport/smtp/commands.rs

@@ -0,0 +1,382 @@
+//! SMTP commands
+
+use crate::{
+    transport::smtp::{
+        authentication::{Credentials, Mechanism},
+        error::Error,
+        extension::{ClientId, MailParameter, RcptParameter},
+        response::Response,
+    },
+    Address,
+};
+#[cfg(feature = "log")]
+use log::debug;
+use std::{
+    convert::AsRef,
+    fmt::{self, Display, Formatter},
+};
+
+/// EHLO command
+#[derive(PartialEq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Ehlo {
+    client_id: ClientId,
+}
+
+impl Display for Ehlo {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "EHLO {}\r\n", self.client_id)
+    }
+}
+
+impl Ehlo {
+    /// Creates a EHLO command
+    pub fn new(client_id: ClientId) -> Ehlo {
+        Ehlo { client_id }
+    }
+}
+
+/// STARTTLS command
+#[derive(PartialEq, Clone, Debug, Copy)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Starttls;
+
+impl Display for Starttls {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        f.write_str("STARTTLS\r\n")
+    }
+}
+
+/// MAIL command
+#[derive(PartialEq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Mail {
+    sender: Option<Address>,
+    parameters: Vec<MailParameter>,
+}
+
+impl Display for Mail {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(
+            f,
+            "MAIL FROM:<{}>",
+            self.sender.as_ref().map(|s| s.as_ref()).unwrap_or("")
+        )?;
+        for parameter in &self.parameters {
+            write!(f, " {}", parameter)?;
+        }
+        f.write_str("\r\n")
+    }
+}
+
+impl Mail {
+    /// Creates a MAIL command
+    pub fn new(sender: Option<Address>, parameters: Vec<MailParameter>) -> Mail {
+        Mail { sender, parameters }
+    }
+}
+
+/// RCPT command
+#[derive(PartialEq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Rcpt {
+    recipient: Address,
+    parameters: Vec<RcptParameter>,
+}
+
+impl Display for Rcpt {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "RCPT TO:<{}>", self.recipient)?;
+        for parameter in &self.parameters {
+            write!(f, " {}", parameter)?;
+        }
+        f.write_str("\r\n")
+    }
+}
+
+impl Rcpt {
+    /// Creates an RCPT command
+    pub fn new(recipient: Address, parameters: Vec<RcptParameter>) -> Rcpt {
+        Rcpt {
+            recipient,
+            parameters,
+        }
+    }
+}
+
+/// DATA command
+#[derive(PartialEq, Clone, Debug, Copy)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Data;
+
+impl Display for Data {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        f.write_str("DATA\r\n")
+    }
+}
+
+/// QUIT command
+#[derive(PartialEq, Clone, Debug, Copy)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Quit;
+
+impl Display for Quit {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        f.write_str("QUIT\r\n")
+    }
+}
+
+/// NOOP command
+#[derive(PartialEq, Clone, Debug, Copy)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Noop;
+
+impl Display for Noop {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        f.write_str("NOOP\r\n")
+    }
+}
+
+/// HELP command
+#[derive(PartialEq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Help {
+    argument: Option<String>,
+}
+
+impl Display for Help {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        f.write_str("HELP")?;
+        if self.argument.is_some() {
+            write!(f, " {}", self.argument.as_ref().unwrap())?;
+        }
+        f.write_str("\r\n")
+    }
+}
+
+impl Help {
+    /// Creates an HELP command
+    pub fn new(argument: Option<String>) -> Help {
+        Help { argument }
+    }
+}
+
+/// VRFY command
+#[derive(PartialEq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Vrfy {
+    argument: String,
+}
+
+impl Display for Vrfy {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "VRFY {}\r\n", self.argument)
+    }
+}
+
+impl Vrfy {
+    /// Creates a VRFY command
+    pub fn new(argument: String) -> Vrfy {
+        Vrfy { argument }
+    }
+}
+
+/// EXPN command
+#[derive(PartialEq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Expn {
+    argument: String,
+}
+
+impl Display for Expn {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "EXPN {}\r\n", self.argument)
+    }
+}
+
+impl Expn {
+    /// Creates an EXPN command
+    pub fn new(argument: String) -> Expn {
+        Expn { argument }
+    }
+}
+
+/// RSET command
+#[derive(PartialEq, Clone, Debug, Copy)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Rset;
+
+impl Display for Rset {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        f.write_str("RSET\r\n")
+    }
+}
+
+/// AUTH command
+#[derive(PartialEq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Auth {
+    mechanism: Mechanism,
+    credentials: Credentials,
+    challenge: Option<String>,
+    response: Option<String>,
+}
+
+impl Display for Auth {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        let encoded_response = self
+            .response
+            .as_ref()
+            .map(|r| base64::encode_config(r.as_bytes(), base64::STANDARD));
+
+        if self.mechanism.supports_initial_response() {
+            write!(f, "AUTH {} {}", self.mechanism, encoded_response.unwrap())?;
+        } else {
+            match encoded_response {
+                Some(response) => f.write_str(&response)?,
+                None => write!(f, "AUTH {}", self.mechanism)?,
+            }
+        }
+        f.write_str("\r\n")
+    }
+}
+
+impl Auth {
+    /// Creates an AUTH command (from a challenge if provided)
+    pub fn new(
+        mechanism: Mechanism,
+        credentials: Credentials,
+        challenge: Option<String>,
+    ) -> Result<Auth, Error> {
+        let response = if mechanism.supports_initial_response() || challenge.is_some() {
+            Some(mechanism.response(&credentials, challenge.as_deref())?)
+        } else {
+            None
+        };
+        Ok(Auth {
+            mechanism,
+            credentials,
+            challenge,
+            response,
+        })
+    }
+
+    /// Creates an AUTH command from a response that needs to be a
+    /// valid challenge (with 334 response code)
+    pub fn new_from_response(
+        mechanism: Mechanism,
+        credentials: Credentials,
+        response: &Response,
+    ) -> Result<Auth, Error> {
+        if !response.has_code(334) {
+            return Err(Error::ResponseParsing("Expecting a challenge"));
+        }
+
+        let encoded_challenge = response
+            .first_word()
+            .ok_or(Error::ResponseParsing("Could not read auth challenge"))?;
+        #[cfg(feature = "log")]
+        debug!("auth encoded challenge: {}", encoded_challenge);
+
+        let decoded_challenge = String::from_utf8(base64::decode(&encoded_challenge)?)?;
+        #[cfg(feature = "log")]
+        debug!("auth decoded challenge: {}", decoded_challenge);
+
+        let response = Some(mechanism.response(&credentials, Some(decoded_challenge.as_ref()))?);
+
+        Ok(Auth {
+            mechanism,
+            credentials,
+            challenge: Some(decoded_challenge),
+            response,
+        })
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::transport::smtp::extension::MailBodyParameter;
+    use std::str::FromStr;
+
+    #[test]
+    fn test_display() {
+        let id = ClientId::Domain("localhost".to_string());
+        let email = Address::from_str("test@example.com").unwrap();
+        let mail_parameter = MailParameter::Other {
+            keyword: "TEST".to_string(),
+            value: Some("value".to_string()),
+        };
+        let rcpt_parameter = RcptParameter::Other {
+            keyword: "TEST".to_string(),
+            value: Some("value".to_string()),
+        };
+        assert_eq!(format!("{}", Ehlo::new(id)), "EHLO localhost\r\n");
+        assert_eq!(
+            format!("{}", Mail::new(Some(email.clone()), vec![])),
+            "MAIL FROM:<test@example.com>\r\n"
+        );
+        assert_eq!(format!("{}", Mail::new(None, vec![])), "MAIL FROM:<>\r\n");
+        assert_eq!(
+            format!(
+                "{}",
+                Mail::new(Some(email.clone()), vec![MailParameter::Size(42)])
+            ),
+            "MAIL FROM:<test@example.com> SIZE=42\r\n"
+        );
+        assert_eq!(
+            format!(
+                "{}",
+                Mail::new(
+                    Some(email.clone()),
+                    vec![
+                        MailParameter::Size(42),
+                        MailParameter::Body(MailBodyParameter::EightBitMime),
+                        mail_parameter,
+                    ],
+                )
+            ),
+            "MAIL FROM:<test@example.com> SIZE=42 BODY=8BITMIME TEST=value\r\n"
+        );
+        assert_eq!(
+            format!("{}", Rcpt::new(email.clone(), vec![])),
+            "RCPT TO:<test@example.com>\r\n"
+        );
+        assert_eq!(
+            format!("{}", Rcpt::new(email.clone(), vec![rcpt_parameter])),
+            "RCPT TO:<test@example.com> TEST=value\r\n"
+        );
+        assert_eq!(format!("{}", Quit), "QUIT\r\n");
+        assert_eq!(format!("{}", Data), "DATA\r\n");
+        assert_eq!(format!("{}", Noop), "NOOP\r\n");
+        assert_eq!(format!("{}", Help::new(None)), "HELP\r\n");
+        assert_eq!(
+            format!("{}", Help::new(Some("test".to_string()))),
+            "HELP test\r\n"
+        );
+        assert_eq!(
+            format!("{}", Vrfy::new("test".to_string())),
+            "VRFY test\r\n"
+        );
+        assert_eq!(
+            format!("{}", Expn::new("test".to_string())),
+            "EXPN test\r\n"
+        );
+        assert_eq!(format!("{}", Rset), "RSET\r\n");
+        let credentials = Credentials::new("user".to_string(), "password".to_string());
+        assert_eq!(
+            format!(
+                "{}",
+                Auth::new(Mechanism::Plain, credentials.clone(), None).unwrap()
+            ),
+            "AUTH PLAIN AHVzZXIAcGFzc3dvcmQ=\r\n"
+        );
+        assert_eq!(
+            format!(
+                "{}",
+                Auth::new(Mechanism::Login, credentials.clone(), None).unwrap()
+            ),
+            "AUTH LOGIN\r\n"
+        );
+    }
+}

src/transport/smtp/error.rs

@@ -0,0 +1,154 @@
+//! Error and result type for SMTP clients
+
+use self::Error::*;
+use crate::transport::smtp::response::{Response, Severity};
+use base64::DecodeError;
+use std::{
+    error::Error as StdError,
+    fmt::{self, Display, Formatter},
+    io,
+    string::FromUtf8Error,
+};
+
+/// An enum of all error kinds.
+#[derive(Debug)]
+pub enum Error {
+    /// Transient SMTP error, 4xx reply code
+    ///
+    /// [RFC 5321, section 4.2.1](https://tools.ietf.org/html/rfc5321#section-4.2.1)
+    Transient(Response),
+    /// Permanent SMTP error, 5xx reply code
+    ///
+    /// [RFC 5321, section 4.2.1](https://tools.ietf.org/html/rfc5321#section-4.2.1)
+    Permanent(Response),
+    /// Error parsing a response
+    ResponseParsing(&'static str),
+    /// Error parsing a base64 string in response
+    ChallengeParsing(DecodeError),
+    /// Error parsing UTF8in response
+    Utf8Parsing(FromUtf8Error),
+    /// Internal client error
+    Client(&'static str),
+    /// DNS resolution error
+    Resolution,
+    /// IO error
+    Io(io::Error),
+    /// TLS error
+    #[cfg(feature = "native-tls")]
+    Tls(native_tls::Error),
+    /// Parsing error
+    Parsing(nom::error::ErrorKind),
+    /// Invalid hostname
+    #[cfg(feature = "rustls-tls")]
+    InvalidDNSName(webpki::InvalidDNSNameError),
+    #[cfg(feature = "r2d2")]
+    Pool(r2d2::Error),
+}
+
+impl Display for Error {
+    fn fmt(&self, fmt: &mut Formatter) -> Result<(), fmt::Error> {
+        match *self {
+            // Try to display the first line of the server's response that usually
+            // contains a short humanly readable error message
+            Transient(ref err) => fmt.write_str(match err.first_line() {
+                Some(line) => line,
+                None => "transient error during SMTP transaction",
+            }),
+            Permanent(ref err) => fmt.write_str(match err.first_line() {
+                Some(line) => line,
+                None => "permanent error during SMTP transaction",
+            }),
+            ResponseParsing(err) => fmt.write_str(err),
+            ChallengeParsing(ref err) => err.fmt(fmt),
+            Utf8Parsing(ref err) => err.fmt(fmt),
+            Resolution => fmt.write_str("could not resolve hostname"),
+            Client(err) => fmt.write_str(err),
+            Io(ref err) => err.fmt(fmt),
+            #[cfg(feature = "native-tls")]
+            Tls(ref err) => err.fmt(fmt),
+            Parsing(ref err) => fmt.write_str(err.description()),
+            #[cfg(feature = "rustls-tls")]
+            InvalidDNSName(ref err) => err.fmt(fmt),
+            #[cfg(feature = "r2d2")]
+            Pool(ref err) => err.fmt(fmt),
+        }
+    }
+}
+
+impl StdError for Error {
+    fn source(&self) -> Option<&(dyn StdError + 'static)> {
+        match *self {
+            ChallengeParsing(ref err) => Some(&*err),
+            Utf8Parsing(ref err) => Some(&*err),
+            Io(ref err) => Some(&*err),
+            #[cfg(feature = "native-tls")]
+            Tls(ref err) => Some(&*err),
+            _ => None,
+        }
+    }
+}
+
+impl From<io::Error> for Error {
+    fn from(err: io::Error) -> Error {
+        Io(err)
+    }
+}
+
+#[cfg(feature = "native-tls")]
+impl From<native_tls::Error> for Error {
+    fn from(err: native_tls::Error) -> Error {
+        Tls(err)
+    }
+}
+
+impl From<nom::Err<(&str, nom::error::ErrorKind)>> for Error {
+    fn from(err: nom::Err<(&str, nom::error::ErrorKind)>) -> Error {
+        Parsing(match err {
+            nom::Err::Incomplete(_) => nom::error::ErrorKind::Complete,
+            nom::Err::Failure((_, k)) => k,
+            nom::Err::Error((_, k)) => k,
+        })
+    }
+}
+
+impl From<DecodeError> for Error {
+    fn from(err: DecodeError) -> Error {
+        ChallengeParsing(err)
+    }
+}
+
+impl From<FromUtf8Error> for Error {
+    fn from(err: FromUtf8Error) -> Error {
+        Utf8Parsing(err)
+    }
+}
+
+#[cfg(feature = "rustls-tls")]
+impl From<webpki::InvalidDNSNameError> for Error {
+    fn from(err: webpki::InvalidDNSNameError) -> Error {
+        InvalidDNSName(err)
+    }
+}
+
+#[cfg(feature = "r2d2")]
+impl From<r2d2::Error> for Error {
+    fn from(err: r2d2::Error) -> Error {
+        Pool(err)
+    }
+}
+
+impl From<Response> for Error {
+    fn from(response: Response) -> Error {
+        match response.code.severity {
+            Severity::TransientNegativeCompletion => Transient(response),
+            Severity::PermanentNegativeCompletion => Permanent(response),
+            _ => Client("Unknown error code"),
+        }
+    }
+}
+
+impl From<&'static str> for Error {
+    fn from(string: &'static str) -> Error {
+        Client(string)
+    }
+}

src/transport/smtp/extension.rs

@@ -0,0 +1,411 @@
+//! ESMTP features
+
+use crate::transport::smtp::{
+    authentication::Mechanism, error::Error, response::Response, util::XText,
+};
+use std::{
+    collections::HashSet,
+    fmt::{self, Display, Formatter},
+    net::{Ipv4Addr, Ipv6Addr},
+    result::Result,
+};
+
+/// Default client id
+const DEFAULT_DOMAIN_CLIENT_ID: &str = "localhost";
+
+/// Client identifier, the parameter to `EHLO`
+#[derive(PartialEq, Eq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub enum ClientId {
+    /// A fully-qualified domain name
+    Domain(String),
+    /// An IPv4 address
+    Ipv4(Ipv4Addr),
+    /// An IPv6 address
+    Ipv6(Ipv6Addr),
+}
+
+impl Display for ClientId {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        match *self {
+            ClientId::Domain(ref value) => f.write_str(value),
+            ClientId::Ipv4(ref value) => write!(f, "{}", value),
+            ClientId::Ipv6(ref value) => write!(f, "{}", value),
+        }
+    }
+}
+
+impl ClientId {
+    /// Creates a new `ClientId` from a fully qualified domain name
+    pub fn new(domain: String) -> ClientId {
+        ClientId::Domain(domain)
+    }
+
+    /// Defines a `ClientId` with the current hostname, of `localhost` if hostname could not be
+    /// found
+    #[cfg(feature = "hostname")]
+    pub fn hostname() -> ClientId {
+        ClientId::Domain(
+            hostname::get()
+                .map_err(|_| ())
+                .and_then(|s| s.into_string().map_err(|_| ()))
+                .unwrap_or_else(|_| DEFAULT_DOMAIN_CLIENT_ID.to_string()),
+        )
+    }
+    #[cfg(not(feature = "hostname"))]
+    pub fn hostname() -> ClientId {
+        ClientId::Domain(DEFAULT_DOMAIN_CLIENT_ID.to_string())
+    }
+}
+
+/// Supported ESMTP keywords
+#[derive(PartialEq, Eq, Hash, Copy, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub enum Extension {
+    /// 8BITMIME keyword
+    ///
+    /// RFC 6152: https://tools.ietf.org/html/rfc6152
+    EightBitMime,
+    /// SMTPUTF8 keyword
+    ///
+    /// RFC 6531: https://tools.ietf.org/html/rfc6531
+    SmtpUtfEight,
+    /// STARTTLS keyword
+    ///
+    /// RFC 2487: https://tools.ietf.org/html/rfc2487
+    StartTls,
+    /// AUTH mechanism
+    Authentication(Mechanism),
+}
+
+impl Display for Extension {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        match *self {
+            Extension::EightBitMime => write!(f, "8BITMIME"),
+            Extension::SmtpUtfEight => write!(f, "SMTPUTF8"),
+            Extension::StartTls => write!(f, "STARTTLS"),
+            Extension::Authentication(ref mechanism) => write!(f, "AUTH {}", mechanism),
+        }
+    }
+}
+
+/// Contains information about an SMTP server
+#[derive(Clone, Debug, Eq, PartialEq, Default)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct ServerInfo {
+    /// Server name
+    ///
+    /// The name given in the server banner
+    pub name: String,
+    /// ESMTP features supported by the server
+    ///
+    /// It contains the features supported by the server and known by the `Extension` module.
+    pub features: HashSet<Extension>,
+}
+
+impl Display for ServerInfo {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(
+            f,
+            "{} with {}",
+            self.name,
+            if self.features.is_empty() {
+                "no supported features".to_string()
+            } else {
+                format!("{:?}", self.features)
+            }
+        )
+    }
+}
+
+impl ServerInfo {
+    /// Parses a EHLO response to create a `ServerInfo`
+    pub fn from_response(response: &Response) -> Result<ServerInfo, Error> {
+        let name = match response.first_word() {
+            Some(name) => name,
+            None => return Err(Error::ResponseParsing("Could not read server name")),
+        };
+
+        let mut features: HashSet<Extension> = HashSet::new();
+
+        for line in response.message.as_slice() {
+            if line.is_empty() {
+                continue;
+            }
+
+            let mut split = line.split_whitespace();
+            match split.next().unwrap() {
+                "8BITMIME" => {
+                    features.insert(Extension::EightBitMime);
+                }
+                "SMTPUTF8" => {
+                    features.insert(Extension::SmtpUtfEight);
+                }
+                "STARTTLS" => {
+                    features.insert(Extension::StartTls);
+                }
+                "AUTH" => {
+                    for mechanism in split {
+                        match mechanism {
+                            "PLAIN" => {
+                                features.insert(Extension::Authentication(Mechanism::Plain));
+                            }
+                            "LOGIN" => {
+                                features.insert(Extension::Authentication(Mechanism::Login));
+                            }
+                            "XOAUTH2" => {
+                                features.insert(Extension::Authentication(Mechanism::Xoauth2));
+                            }
+                            _ => (),
+                        }
+                    }
+                }
+                _ => (),
+            };
+        }
+
+        Ok(ServerInfo {
+            name: name.to_string(),
+            features,
+        })
+    }
+
+    /// Checks if the server supports an ESMTP feature
+    pub fn supports_feature(&self, keyword: Extension) -> bool {
+        self.features.contains(&keyword)
+    }
+
+    /// Checks if the server supports an ESMTP feature
+    pub fn supports_auth_mechanism(&self, mechanism: Mechanism) -> bool {
+        self.features
+            .contains(&Extension::Authentication(mechanism))
+    }
+
+    /// Gets a compatible mechanism from list
+    pub fn get_auth_mechanism(&self, mechanisms: &[Mechanism]) -> Option<Mechanism> {
+        for mechanism in mechanisms {
+            if self.supports_auth_mechanism(*mechanism) {
+                return Some(*mechanism);
+            }
+        }
+        None
+    }
+}
+
+/// A `MAIL FROM` extension parameter
+#[derive(PartialEq, Eq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub enum MailParameter {
+    /// `BODY` parameter
+    Body(MailBodyParameter),
+    /// `SIZE` parameter
+    Size(usize),
+    /// `SMTPUTF8` parameter
+    SmtpUtfEight,
+    /// Custom parameter
+    Other {
+        /// Parameter keyword
+        keyword: String,
+        /// Parameter value
+        value: Option<String>,
+    },
+}
+
+impl Display for MailParameter {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        match *self {
+            MailParameter::Body(ref value) => write!(f, "BODY={}", value),
+            MailParameter::Size(size) => write!(f, "SIZE={}", size),
+            MailParameter::SmtpUtfEight => f.write_str("SMTPUTF8"),
+            MailParameter::Other {
+                ref keyword,
+                value: Some(ref value),
+            } => write!(f, "{}={}", keyword, XText(value)),
+            MailParameter::Other {
+                ref keyword,
+                value: None,
+            } => f.write_str(keyword),
+        }
+    }
+}
+
+/// Values for the `BODY` parameter to `MAIL FROM`
+#[derive(PartialEq, Eq, Clone, Debug, Copy)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub enum MailBodyParameter {
+    /// `7BIT`
+    SevenBit,
+    /// `8BITMIME`
+    EightBitMime,
+}
+
+impl Display for MailBodyParameter {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        match *self {
+            MailBodyParameter::SevenBit => f.write_str("7BIT"),
+            MailBodyParameter::EightBitMime => f.write_str("8BITMIME"),
+        }
+    }
+}
+
+/// A `RCPT TO` extension parameter
+#[derive(PartialEq, Eq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub enum RcptParameter {
+    /// Custom parameter
+    Other {
+        /// Parameter keyword
+        keyword: String,
+        /// Parameter value
+        value: Option<String>,
+    },
+}
+
+impl Display for RcptParameter {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        match *self {
+            RcptParameter::Other {
+                ref keyword,
+                value: Some(ref value),
+            } => write!(f, "{}={}", keyword, XText(value)),
+            RcptParameter::Other {
+                ref keyword,
+                value: None,
+            } => f.write_str(keyword),
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+
+    use super::{ClientId, Extension, ServerInfo};
+    use crate::transport::smtp::{
+        authentication::Mechanism,
+        response::{Category, Code, Detail, Response, Severity},
+    };
+    use std::collections::HashSet;
+
+    #[test]
+    fn test_clientid_fmt() {
+        assert_eq!(
+            format!("{}", ClientId::new("test".to_string())),
+            "test".to_string()
+        );
+    }
+
+    #[test]
+    fn test_extension_fmt() {
+        assert_eq!(
+            format!("{}", Extension::EightBitMime),
+            "8BITMIME".to_string()
+        );
+        assert_eq!(
+            format!("{}", Extension::Authentication(Mechanism::Plain)),
+            "AUTH PLAIN".to_string()
+        );
+    }
+
+    #[test]
+    fn test_serverinfo_fmt() {
+        let mut eightbitmime = HashSet::new();
+        assert!(eightbitmime.insert(Extension::EightBitMime));
+
+        assert_eq!(
+            format!(
+                "{}",
+                ServerInfo {
+                    name: "name".to_string(),
+                    features: eightbitmime.clone(),
+                }
+            ),
+            "name with {EightBitMime}".to_string()
+        );
+
+        let empty = HashSet::new();
+
+        assert_eq!(
+            format!(
+                "{}",
+                ServerInfo {
+                    name: "name".to_string(),
+                    features: empty,
+                }
+            ),
+            "name with no supported features".to_string()
+        );
+
+        let mut plain = HashSet::new();
+        assert!(plain.insert(Extension::Authentication(Mechanism::Plain)));
+
+        assert_eq!(
+            format!(
+                "{}",
+                ServerInfo {
+                    name: "name".to_string(),
+                    features: plain.clone(),
+                }
+            ),
+            "name with {Authentication(Plain)}".to_string()
+        );
+    }
+
+    #[test]
+    fn test_serverinfo() {
+        let response = Response::new(
+            Code::new(
+                Severity::PositiveCompletion,
+                Category::Unspecified4,
+                Detail::One,
+            ),
+            vec![
+                "me".to_string(),
+                "8BITMIME".to_string(),
+                "SIZE 42".to_string(),
+            ],
+        );
+
+        let mut features = HashSet::new();
+        assert!(features.insert(Extension::EightBitMime));
+
+        let server_info = ServerInfo {
+            name: "me".to_string(),
+            features,
+        };
+
+        assert_eq!(ServerInfo::from_response(&response).unwrap(), server_info);
+
+        assert!(server_info.supports_feature(Extension::EightBitMime));
+        assert!(!server_info.supports_feature(Extension::StartTls));
+
+        let response2 = Response::new(
+            Code::new(
+                Severity::PositiveCompletion,
+                Category::Unspecified4,
+                Detail::One,
+            ),
+            vec![
+                "me".to_string(),
+                "AUTH PLAIN CRAM-MD5 XOAUTH2 OTHER".to_string(),
+                "8BITMIME".to_string(),
+                "SIZE 42".to_string(),
+            ],
+        );
+
+        let mut features2 = HashSet::new();
+        assert!(features2.insert(Extension::EightBitMime));
+        assert!(features2.insert(Extension::Authentication(Mechanism::Plain),));
+        assert!(features2.insert(Extension::Authentication(Mechanism::Xoauth2),));
+
+        let server_info2 = ServerInfo {
+            name: "me".to_string(),
+            features: features2,
+        };
+
+        assert_eq!(ServerInfo::from_response(&response2).unwrap(), server_info2);
+
+        assert!(server_info2.supports_feature(Extension::EightBitMime));
+        assert!(server_info2.supports_auth_mechanism(Mechanism::Plain));
+        assert!(!server_info2.supports_feature(Extension::StartTls));
+    }
+}

src/transport/smtp/mod.rs

@@ -0,0 +1,478 @@
+//! The SMTP transport sends emails using the SMTP protocol.
+//!
+//! This SMTP client follows [RFC
+//! 5321](https://tools.ietf.org/html/rfc5321), and is designed to efficiently send emails from an
+//! application to a relay email server, as it relies as much as possible on the relay server
+//! for sanity and RFC compliance checks.
+//!
+//! It implements the following extensions:
+//!
+//! * 8BITMIME ([RFC 6152](https://tools.ietf.org/html/rfc6152))
+//! * AUTH ([RFC 4954](http://tools.ietf.org/html/rfc4954)) with PLAIN, LOGIN and XOAUTH2 mechanisms
+//! * STARTTLS ([RFC 2487](http://tools.ietf.org/html/rfc2487))
+//!
+//! #### SMTP Transport
+//!
+//! This transport uses the SMTP protocol to send emails over the network (locally or remotely).
+//!
+//! It is designed to be:
+//!
+//! * Secured: email are encrypted by default
+//! * Modern: unicode support for email content and sender/recipient addresses when compatible
+//! * Fast: supports connection reuse and pooling
+//!
+//! This client is designed to send emails to a relay server, and should *not* be used to send
+//! emails directly to the destination.
+//!
+//! The relay server can be the local email server, a specific host or a third-party service.
+//!
+//! #### Simple example
+//!
+//! This is the most basic example of usage:
+//!
+//! ```rust,no_run
+//! # #[cfg(feature = "smtp-transport")]
+//! # {
+//! use lettre::{Message, Transport, SmtpTransport};
+//!
+//! let email = Message::builder()
+//!     .from("NoBody <nobody@domain.tld>".parse().unwrap())
+//!     .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+//!     .to("Hei <hei@domain.tld>".parse().unwrap())
+//!     .subject("Happy new year")
+//!     .body("Be happy!")
+//!     .unwrap();
+//!
+//! // Create local transport on port 25
+//! let sender = SmtpTransport::unencrypted_localhost();
+//! // Send the email on local relay
+//! let result = sender.send(&email);
+//!
+//! assert!(result.is_ok());
+//! # }
+//! ```
+//!
+//! #### Complete example
+//!
+//! ```todo
+//! # #[cfg(feature = "smtp-transport")]
+//! # {
+//! use lettre::transport::smtp::authentication::{Credentials, Mechanism};
+//! use lettre::{Email, Envelope, Transport, SmtpClient};
+//! use lettre::transport::smtp::extension::ClientId;
+//!
+//! let email_1 = Email::new(
+//!     Envelope::new(
+//!         Some(EmailAddress::new("user@localhost".to_string()).unwrap()),
+//!         vec![EmailAddress::new("root@localhost".to_string()).unwrap()],
+//!     ).unwrap(),
+//!     "id1".to_string(),
+//!     "Hello world".to_string().into_bytes(),
+//! );
+//!
+//! let email_2 = Email::new(
+//!     Envelope::new(
+//!         Some(EmailAddress::new("user@localhost".to_string()).unwrap()),
+//!         vec![EmailAddress::new("root@localhost".to_string()).unwrap()],
+//!     ).unwrap(),
+//!     "id2".to_string(),
+//!     "Hello world a second time".to_string().into_bytes(),
+//! );
+//!
+//! // Connect to a remote server on a custom port
+//! let mut mailer = SmtpClient::new_simple("server.tld").unwrap()
+//!    // Set the name sent during EHLO/HELO, default is `localhost`
+//!    .hello_name(ClientId::Domain("my.hostname.tld".to_string()))
+//!    // Add credentials for authentication
+//!    .credentials(Credentials::new("username".to_string(), "password".to_string()))
+//!    // Enable SMTPUTF8 if the server supports it
+//!    .smtp_utf8(true)
+//!    // Configure expected authentication mechanism
+//!    .authentication_mechanism(Mechanism::Plain)
+//!    // Enable connection reuse
+//!    .connection_reuse(ConnectionReuseParameters::ReuseUnlimited).transport();
+//!
+//! let result_1 = mailer.send(&email_1);
+//! assert!(result_1.is_ok());
+//!
+//! // The second email will use the same connection
+//! let result_2 = mailer.send(&email_2);
+//! assert!(result_2.is_ok());
+//!
+//! // Explicitly close the SMTP transaction as we enabled connection reuse
+//! mailer.close();
+//! # }
+//! ```
+//!
+//! You can specify custom TLS settings:
+//!
+//! ```todo
+//! # #[cfg(feature = "native-tls")]
+//! # {
+//! use lettre::{
+//!     ClientSecurity, ClientTlsParameters, EmailAddress, Envelope,
+//!     Email, SmtpClient, Transport,
+//! };
+//! use lettre::transport::smtp::authentication::{Credentials, Mechanism};
+//! use lettre::transport::smtp::ConnectionReuseParameters;
+//! use native_tls::{Protocol, TlsConnector};
+//!
+//!     let email = Email::new(
+//!         Envelope::new(
+//!             Some(EmailAddress::new("user@localhost".to_string()).unwrap()),
+//!             vec![EmailAddress::new("root@localhost".to_string()).unwrap()],
+//!         ).unwrap(),
+//!         "message_id".to_string(),
+//!         "Hello world".to_string().into_bytes(),
+//!     );
+//!
+//!     let mut tls_builder = TlsConnector::builder();
+//!     tls_builder.min_protocol_version(Some(Protocol::Tlsv10));
+//!     let tls_parameters =
+//!         ClientTlsParameters::new(
+//!             "smtp.example.com".to_string(),
+//!             tls_builder.build().unwrap()
+//!         );
+//!
+//!     let mut mailer = SmtpClient::new(
+//!         ("smtp.example.com", 465), ClientSecurity::Wrapper(tls_parameters)
+//!     ).unwrap()
+//!         .authentication_mechanism(Mechanism::Login)
+//!         .credentials(Credentials::new(
+//!             "example_username".to_string(), "example_password".to_string()
+//!         ))
+//!         .connection_reuse(ConnectionReuseParameters::ReuseUnlimited)
+//!         .transport();
+//!
+//!     let result = mailer.send(&email);
+//!
+//!     assert!(result.is_ok());
+//!
+//!     mailer.close();
+//! # }
+//! ```
+//!
+//! #### Lower level
+//!
+//! You can also send commands, here is a simple email transaction without
+//! error handling:
+//!
+//! ```rust,no_run
+//! # #[cfg(feature = "smtp-transport")]
+//! # {
+//! use lettre::transport::smtp::{SMTP_PORT, extension::ClientId, commands::*, client::SmtpConnection};
+//!
+//! let hello = ClientId::new("my_hostname".to_string());
+//! let mut client = SmtpConnection::connect(&("localhost", SMTP_PORT), None, &hello, None).unwrap();
+//! client.command(
+//!         Mail::new(Some("user@example.com".parse().unwrap()), vec![])
+//!     ).unwrap();
+//! client.command(
+//!         Rcpt::new("user@example.org".parse().unwrap(), vec![])
+//!       ).unwrap();
+//! client.command(Data).unwrap();
+//! client.message("Test email".as_bytes()).unwrap();
+//! client.command(Quit).unwrap();
+//! # }
+//! ```
+
+#[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+use crate::transport::smtp::client::net::TlsParameters;
+use crate::{
+    transport::smtp::{
+        authentication::{Credentials, Mechanism, DEFAULT_MECHANISMS},
+        client::SmtpConnection,
+        error::Error,
+        extension::ClientId,
+        response::Response,
+    },
+    Envelope, Transport,
+};
+#[cfg(feature = "native-tls")]
+use native_tls::{Protocol, TlsConnector};
+#[cfg(feature = "r2d2")]
+use r2d2::{Builder, Pool};
+#[cfg(feature = "rustls-tls")]
+use rustls::ClientConfig;
+use std::time::Duration;
+#[cfg(feature = "rustls-tls")]
+use webpki_roots::TLS_SERVER_ROOTS;
+
+pub mod authentication;
+pub mod client;
+pub mod commands;
+pub mod error;
+pub mod extension;
+#[cfg(feature = "r2d2")]
+pub mod pool;
+pub mod response;
+pub mod util;
+
+// Registered port numbers:
+// https://www.iana.
+// org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml
+
+/// Default smtp port
+pub const SMTP_PORT: u16 = 25;
+/// Default submission port
+pub const SUBMISSION_PORT: u16 = 587;
+/// Default submission over TLS port
+///
+/// https://tools.ietf.org/html/rfc8314
+pub const SUBMISSIONS_PORT: u16 = 465;
+
+/// Default timeout
+pub const DEFAULT_TIMEOUT: Duration = Duration::from_secs(60);
+
+/// Accepted protocols by default.
+/// This removes TLS 1.0 and 1.1 compared to tls-native defaults.
+// This is also rustls' default behavior
+#[cfg(feature = "native-tls")]
+const DEFAULT_TLS_MIN_PROTOCOL: Protocol = Protocol::Tlsv12;
+
+/// How to apply TLS to a client connection
+#[derive(Clone)]
+#[allow(missing_debug_implementations, missing_copy_implementations)]
+pub enum Tls {
+    /// Insecure connection only (for testing purposes)
+    None,
+    /// Start with insecure connection and use `STARTTLS` when available
+    #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+    Opportunistic(TlsParameters),
+    /// Start with insecure connection and require `STARTTLS`
+    #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+    Required(TlsParameters),
+    /// Use TLS wrapped connection
+    #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+    Wrapper(TlsParameters),
+}
+
+#[allow(missing_debug_implementations)]
+#[derive(Clone)]
+pub struct SmtpTransport {
+    #[cfg(feature = "r2d2")]
+    inner: Pool<SmtpClient>,
+    #[cfg(not(feature = "r2d2"))]
+    inner: SmtpClient,
+}
+
+impl Transport for SmtpTransport {
+    type Ok = Response;
+    type Error = Error;
+
+    /// Sends an email
+    fn send_raw(&self, envelope: &Envelope, email: &[u8]) -> Result<Self::Ok, Self::Error> {
+        #[cfg(feature = "r2d2")]
+        let mut conn = self.inner.get()?;
+        #[cfg(not(feature = "r2d2"))]
+        let mut conn = self.inner.connection()?;
+
+        let result = conn.send(envelope, email)?;
+
+        #[cfg(not(feature = "r2d2"))]
+        conn.quit()?;
+
+        Ok(result)
+    }
+}
+
+impl SmtpTransport {
+    /// Creates a new SMTP client
+    ///
+    /// Defaults are:
+    ///
+    /// * No authentication
+    /// * A 60 seconds timeout for smtp commands
+    /// * Port 587
+    ///
+    /// Consider using [`SmtpTransport::new`] instead, if possible.
+    pub fn builder<T: Into<String>>(server: T) -> SmtpTransportBuilder {
+        let mut new = SmtpInfo::default();
+        new.server = server.into();
+        SmtpTransportBuilder { info: new }
+    }
+
+    /// Simple and secure transport, should be used when possible.
+    /// Creates an encrypted transport over submissions port, using the provided domain
+    /// to validate TLS certificates.
+    #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+    pub fn relay(relay: &str) -> Result<SmtpTransportBuilder, Error> {
+        #[cfg(feature = "native-tls")]
+        let mut tls_builder = TlsConnector::builder();
+        #[cfg(feature = "native-tls")]
+        tls_builder.min_protocol_version(Some(DEFAULT_TLS_MIN_PROTOCOL));
+        #[cfg(feature = "native-tls")]
+        let tls_parameters = TlsParameters::new(relay.to_string(), tls_builder.build()?);
+
+        #[cfg(feature = "rustls-tls")]
+        let mut tls = ClientConfig::new();
+        #[cfg(feature = "rustls-tls")]
+        tls.root_store.add_server_trust_anchors(&TLS_SERVER_ROOTS);
+        #[cfg(feature = "rustls-tls")]
+        let tls_parameters = TlsParameters::new(relay.to_string(), tls);
+
+        Ok(Self::builder(relay)
+            .port(SUBMISSIONS_PORT)
+            .tls(Tls::Wrapper(tls_parameters)))
+    }
+
+    /// Creates a new local SMTP client to port 25
+    ///
+    /// Shortcut for local unencrypted relay (typical local email daemon that will handle relaying)
+    pub fn unencrypted_localhost() -> SmtpTransport {
+        Self::builder("localhost").port(SMTP_PORT).build()
+    }
+}
+
+#[allow(missing_debug_implementations)]
+#[derive(Clone)]
+struct SmtpInfo {
+    /// Name sent during EHLO
+    hello_name: ClientId,
+    /// Server we are connecting to
+    server: String,
+    /// Port to connect to
+    port: u16,
+    /// TLS security configuration
+    tls: Tls,
+    /// Optional enforced authentication mechanism
+    authentication: Vec<Mechanism>,
+    /// Credentials
+    credentials: Option<Credentials>,
+    /// Define network timeout
+    /// It can be changed later for specific needs (like a different timeout for each SMTP command)
+    timeout: Option<Duration>,
+}
+
+impl Default for SmtpInfo {
+    fn default() -> Self {
+        Self {
+            server: "localhost".to_string(),
+            port: SUBMISSION_PORT,
+            hello_name: ClientId::hostname(),
+            credentials: None,
+            authentication: DEFAULT_MECHANISMS.into(),
+            timeout: Some(DEFAULT_TIMEOUT),
+            tls: Tls::None,
+        }
+    }
+}
+
+/// Contains client configuration
+#[allow(missing_debug_implementations)]
+#[derive(Clone)]
+pub struct SmtpTransportBuilder {
+    info: SmtpInfo,
+}
+
+/// Builder for the SMTP `SmtpTransport`
+impl SmtpTransportBuilder {
+    /// Set the name used during EHLO
+    pub fn hello_name(mut self, name: ClientId) -> Self {
+        self.info.hello_name = name;
+        self
+    }
+
+    /// Set the authentication mechanism to use
+    pub fn credentials(mut self, credentials: Credentials) -> Self {
+        self.info.credentials = Some(credentials);
+        self
+    }
+
+    /// Set the authentication mechanism to use
+    pub fn authentication(mut self, mechanisms: Vec<Mechanism>) -> Self {
+        self.info.authentication = mechanisms;
+        self
+    }
+
+    /// Set the timeout duration
+    pub fn timeout(mut self, timeout: Option<Duration>) -> Self {
+        self.info.timeout = timeout;
+        self
+    }
+
+    /// Set the port to use
+    pub fn port(mut self, port: u16) -> Self {
+        self.info.port = port;
+        self
+    }
+
+    /// Set the TLS settings to use
+    #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+    pub fn tls(mut self, tls: Tls) -> Self {
+        self.info.tls = tls;
+        self
+    }
+
+    /// Build the client
+    fn build_client(self) -> SmtpClient {
+        SmtpClient { info: self.info }
+    }
+
+    /// Build the transport with custom pool settings
+    #[cfg(feature = "r2d2")]
+    pub fn build_with_pool(self, pool: Builder<SmtpClient>) -> SmtpTransport {
+        let pool = pool.build_unchecked(self.build_client());
+        SmtpTransport { inner: pool }
+    }
+
+    /// Build the transport (with default pool if enabled)
+    pub fn build(self) -> SmtpTransport {
+        let client = self.build_client();
+        SmtpTransport {
+            #[cfg(feature = "r2d2")]
+            inner: Pool::builder().max_size(5).build_unchecked(client),
+            #[cfg(not(feature = "r2d2"))]
+            inner: client,
+        }
+    }
+}
+
+/// Build client
+#[derive(Clone)]
+pub struct SmtpClient {
+    info: SmtpInfo,
+}
+
+impl SmtpClient {
+    /// Creates a new connection directly usable to send emails
+    ///
+    /// Handles encryption and authentication
+    pub fn connection(&self) -> Result<SmtpConnection, Error> {
+        let mut conn = SmtpConnection::connect::<(&str, u16)>(
+            (self.info.server.as_ref(), self.info.port),
+            self.info.timeout,
+            &self.info.hello_name,
+            #[allow(clippy::match_single_binding)]
+            match self.info.tls {
+                #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+                Tls::Wrapper(ref tls_parameters) => Some(tls_parameters),
+                _ => None,
+            },
+        )?;
+
+        #[allow(clippy::match_single_binding)]
+        match self.info.tls {
+            #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+            Tls::Opportunistic(ref tls_parameters) => {
+                if conn.can_starttls() {
+                    conn.starttls(tls_parameters, &self.info.hello_name)?;
+                }
+            }
+            #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
+            Tls::Required(ref tls_parameters) => {
+                conn.starttls(tls_parameters, &self.info.hello_name)?;
+            }
+            _ => (),
+        }
+
+        match &self.info.credentials {
+            Some(credentials) => {
+                conn.auth(self.info.authentication.as_slice(), &credentials)?;
+            }
+            None => (),
+        }
+
+        Ok(conn)
+    }
+}

src/transport/smtp/pool.rs

@@ -0,0 +1,22 @@
+use crate::transport::smtp::{client::SmtpConnection, error::Error, SmtpClient};
+use r2d2::ManageConnection;
+
+impl ManageConnection for SmtpClient {
+    type Connection = SmtpConnection;
+    type Error = Error;
+
+    fn connect(&self) -> Result<Self::Connection, Error> {
+        self.connection()
+    }
+
+    fn is_valid(&self, conn: &mut Self::Connection) -> Result<(), Error> {
+        if conn.test_connected() {
+            return Ok(());
+        }
+        Err(Error::Client("is not connected anymore"))
+    }
+
+    fn has_broken(&self, conn: &mut Self::Connection) -> bool {
+        conn.has_broken()
+    }
+}

src/transport/smtp/response.rs

@@ -0,0 +1,568 @@
+//! SMTP response, containing a mandatory return code and an optional text
+//! message
+
+use crate::transport::smtp::Error;
+use nom::{
+    branch::alt,
+    bytes::streaming::{tag, take_until},
+    combinator::{complete, map},
+    multi::many0,
+    sequence::{preceded, tuple},
+    IResult,
+};
+use std::{
+    fmt::{Display, Formatter, Result},
+    result,
+    str::FromStr,
+    string::ToString,
+};
+
+/// First digit indicates severity
+#[derive(PartialEq, Eq, Copy, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub enum Severity {
+    /// 2yx
+    PositiveCompletion = 2,
+    /// 3yz
+    PositiveIntermediate = 3,
+    /// 4yz
+    TransientNegativeCompletion = 4,
+    /// 5yz
+    PermanentNegativeCompletion = 5,
+}
+
+impl Display for Severity {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        write!(f, "{}", *self as u8)
+    }
+}
+
+/// Second digit
+#[derive(PartialEq, Eq, Copy, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub enum Category {
+    /// x0z
+    Syntax = 0,
+    /// x1z
+    Information = 1,
+    /// x2z
+    Connections = 2,
+    /// x3z
+    Unspecified3 = 3,
+    /// x4z
+    Unspecified4 = 4,
+    /// x5z
+    MailSystem = 5,
+}
+
+impl Display for Category {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        write!(f, "{}", *self as u8)
+    }
+}
+
+/// The detail digit of a response code (third digit)
+#[derive(PartialEq, Eq, Copy, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub enum Detail {
+    #[allow(missing_docs)]
+    Zero = 0,
+    #[allow(missing_docs)]
+    One = 1,
+    #[allow(missing_docs)]
+    Two = 2,
+    #[allow(missing_docs)]
+    Three = 3,
+    #[allow(missing_docs)]
+    Four = 4,
+    #[allow(missing_docs)]
+    Five = 5,
+    #[allow(missing_docs)]
+    Six = 6,
+    #[allow(missing_docs)]
+    Seven = 7,
+    #[allow(missing_docs)]
+    Eight = 8,
+    #[allow(missing_docs)]
+    Nine = 9,
+}
+
+impl Display for Detail {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        write!(f, "{}", *self as u8)
+    }
+}
+
+/// Represents a 3 digit SMTP response code
+#[derive(PartialEq, Eq, Copy, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Code {
+    /// First digit of the response code
+    pub severity: Severity,
+    /// Second digit of the response code
+    pub category: Category,
+    /// Third digit
+    pub detail: Detail,
+}
+
+impl Display for Code {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        write!(f, "{}{}{}", self.severity, self.category, self.detail)
+    }
+}
+
+impl Code {
+    /// Creates a new `Code` structure
+    pub fn new(severity: Severity, category: Category, detail: Detail) -> Code {
+        Code {
+            severity,
+            category,
+            detail,
+        }
+    }
+}
+
+/// Contains an SMTP reply, with separated code and message
+///
+/// The text message is optional, only the code is mandatory
+#[derive(PartialEq, Eq, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct Response {
+    /// Response code
+    pub code: Code,
+    /// Server response string (optional)
+    /// Handle multiline responses
+    pub message: Vec<String>,
+}
+
+impl FromStr for Response {
+    type Err = Error;
+
+    fn from_str(s: &str) -> result::Result<Response, Error> {
+        parse_response(s).map(|(_, r)| r).map_err(|e| e.into())
+    }
+}
+
+impl Response {
+    /// Creates a new `Response`
+    pub fn new(code: Code, message: Vec<String>) -> Response {
+        Response { code, message }
+    }
+
+    /// Tells if the response is positive
+    pub fn is_positive(&self) -> bool {
+        match self.code.severity {
+            Severity::PositiveCompletion | Severity::PositiveIntermediate => true,
+            _ => false,
+        }
+    }
+
+    /// Tests code equality
+    pub fn has_code(&self, code: u16) -> bool {
+        self.code.to_string() == code.to_string()
+    }
+
+    /// Returns only the first word of the message if possible
+    pub fn first_word(&self) -> Option<&str> {
+        self.message
+            .first()
+            .and_then(|line| line.split_whitespace().next())
+    }
+
+    /// Returns only the line of the message if possible
+    pub fn first_line(&self) -> Option<&str> {
+        self.message.first().map(String::as_str)
+    }
+}
+
+// Parsers (originally from tokio-smtp)
+
+fn parse_code(i: &str) -> IResult<&str, Code> {
+    let (i, severity) = parse_severity(i)?;
+    let (i, category) = parse_category(i)?;
+    let (i, detail) = parse_detail(i)?;
+    Ok((
+        i,
+        Code {
+            severity,
+            category,
+            detail,
+        },
+    ))
+}
+
+fn parse_severity(i: &str) -> IResult<&str, Severity> {
+    alt((
+        map(tag("2"), |_| Severity::PositiveCompletion),
+        map(tag("3"), |_| Severity::PositiveIntermediate),
+        map(tag("4"), |_| Severity::TransientNegativeCompletion),
+        map(tag("5"), |_| Severity::PermanentNegativeCompletion),
+    ))(i)
+}
+
+fn parse_category(i: &str) -> IResult<&str, Category> {
+    alt((
+        map(tag("0"), |_| Category::Syntax),
+        map(tag("1"), |_| Category::Information),
+        map(tag("2"), |_| Category::Connections),
+        map(tag("3"), |_| Category::Unspecified3),
+        map(tag("4"), |_| Category::Unspecified4),
+        map(tag("5"), |_| Category::MailSystem),
+    ))(i)
+}
+
+fn parse_detail(i: &str) -> IResult<&str, Detail> {
+    alt((
+        map(tag("0"), |_| Detail::Zero),
+        map(tag("1"), |_| Detail::One),
+        map(tag("2"), |_| Detail::Two),
+        map(tag("3"), |_| Detail::Three),
+        map(tag("4"), |_| Detail::Four),
+        map(tag("5"), |_| Detail::Five),
+        map(tag("6"), |_| Detail::Six),
+        map(tag("7"), |_| Detail::Seven),
+        map(tag("8"), |_| Detail::Eight),
+        map(tag("9"), |_| Detail::Nine),
+    ))(i)
+}
+
+pub(crate) fn parse_response(i: &str) -> IResult<&str, Response> {
+    let (i, lines) = many0(tuple((
+        parse_code,
+        preceded(tag("-"), take_until("\r\n")),
+        tag("\r\n"),
+    )))(i)?;
+    let (i, (last_code, last_line)) =
+        tuple((parse_code, preceded(tag(" "), take_until("\r\n"))))(i)?;
+    let (i, _) = complete(tag("\r\n"))(i)?;
+
+    // Check that all codes are equal.
+    if !lines.iter().all(|&(ref code, _, _)| *code == last_code) {
+        return Err(nom::Err::Failure(("", nom::error::ErrorKind::Not)));
+    }
+
+    // Extract text from lines, and append last line.
+    let mut lines: Vec<&str> = lines
+        .into_iter()
+        .map(|(_, text, _)| text)
+        .collect::<Vec<_>>();
+    lines.push(last_line);
+
+    Ok((
+        i,
+        Response {
+            code: last_code,
+            message: lines
+                .iter()
+                .map(ToString::to_string)
+                .collect::<Vec<String>>(),
+        },
+    ))
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_severity_fmt() {
+        assert_eq!(format!("{}", Severity::PositiveCompletion), "2");
+    }
+
+    #[test]
+    fn test_category_fmt() {
+        assert_eq!(format!("{}", Category::Unspecified4), "4");
+    }
+
+    #[test]
+    fn test_code_new() {
+        assert_eq!(
+            Code::new(
+                Severity::TransientNegativeCompletion,
+                Category::Connections,
+                Detail::Zero,
+            ),
+            Code {
+                severity: Severity::TransientNegativeCompletion,
+                category: Category::Connections,
+                detail: Detail::Zero,
+            }
+        );
+    }
+
+    #[test]
+    fn test_code_display() {
+        let code = Code {
+            severity: Severity::TransientNegativeCompletion,
+            category: Category::Connections,
+            detail: Detail::One,
+        };
+
+        assert_eq!(code.to_string(), "421");
+    }
+
+    #[test]
+    fn test_response_from_str() {
+        let raw_response = "250-me\r\n250-8BITMIME\r\n250-SIZE 42\r\n250 AUTH PLAIN CRAM-MD5\r\n";
+        assert_eq!(
+            raw_response.parse::<Response>().unwrap(),
+            Response {
+                code: Code {
+                    severity: Severity::PositiveCompletion,
+                    category: Category::MailSystem,
+                    detail: Detail::Zero,
+                },
+                message: vec![
+                    "me".to_string(),
+                    "8BITMIME".to_string(),
+                    "SIZE 42".to_string(),
+                    "AUTH PLAIN CRAM-MD5".to_string(),
+                ],
+            }
+        );
+
+        let wrong_code = "2506-me\r\n250-8BITMIME\r\n250-SIZE 42\r\n250 AUTH PLAIN CRAM-MD5\r\n";
+        assert!(wrong_code.parse::<Response>().is_err());
+
+        let wrong_end = "250-me\r\n250-8BITMIME\r\n250-SIZE 42\r\n250-AUTH PLAIN CRAM-MD5\r\n";
+        assert!(wrong_end.parse::<Response>().is_err());
+    }
+
+    #[test]
+    fn test_response_is_positive() {
+        assert!(Response::new(
+            Code {
+                severity: Severity::PositiveCompletion,
+                category: Category::MailSystem,
+                detail: Detail::Zero,
+            },
+            vec![
+                "me".to_string(),
+                "8BITMIME".to_string(),
+                "SIZE 42".to_string(),
+            ],
+        )
+        .is_positive());
+        assert!(!Response::new(
+            Code {
+                severity: Severity::TransientNegativeCompletion,
+                category: Category::MailSystem,
+                detail: Detail::Zero,
+            },
+            vec![
+                "me".to_string(),
+                "8BITMIME".to_string(),
+                "SIZE 42".to_string(),
+            ],
+        )
+        .is_positive());
+    }
+
+    #[test]
+    fn test_response_has_code() {
+        assert!(Response::new(
+            Code {
+                severity: Severity::TransientNegativeCompletion,
+                category: Category::MailSystem,
+                detail: Detail::One,
+            },
+            vec![
+                "me".to_string(),
+                "8BITMIME".to_string(),
+                "SIZE 42".to_string(),
+            ],
+        )
+        .has_code(451));
+        assert!(!Response::new(
+            Code {
+                severity: Severity::TransientNegativeCompletion,
+                category: Category::MailSystem,
+                detail: Detail::One,
+            },
+            vec![
+                "me".to_string(),
+                "8BITMIME".to_string(),
+                "SIZE 42".to_string(),
+            ],
+        )
+        .has_code(251));
+    }
+
+    #[test]
+    fn test_response_first_word() {
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: Severity::TransientNegativeCompletion,
+                    category: Category::MailSystem,
+                    detail: Detail::One,
+                },
+                vec![
+                    "me".to_string(),
+                    "8BITMIME".to_string(),
+                    "SIZE 42".to_string(),
+                ],
+            )
+            .first_word(),
+            Some("me")
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: Severity::TransientNegativeCompletion,
+                    category: Category::MailSystem,
+                    detail: Detail::One,
+                },
+                vec![
+                    "me mo".to_string(),
+                    "8BITMIME".to_string(),
+                    "SIZE 42".to_string(),
+                ],
+            )
+            .first_word(),
+            Some("me")
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: Severity::TransientNegativeCompletion,
+                    category: Category::MailSystem,
+                    detail: Detail::One,
+                },
+                vec![],
+            )
+            .first_word(),
+            None
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: Severity::TransientNegativeCompletion,
+                    category: Category::MailSystem,
+                    detail: Detail::One,
+                },
+                vec![" ".to_string()],
+            )
+            .first_word(),
+            None
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: Severity::TransientNegativeCompletion,
+                    category: Category::MailSystem,
+                    detail: Detail::One,
+                },
+                vec!["  ".to_string()],
+            )
+            .first_word(),
+            None
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: Severity::TransientNegativeCompletion,
+                    category: Category::MailSystem,
+                    detail: Detail::One,
+                },
+                vec!["".to_string()],
+            )
+            .first_word(),
+            None
+        );
+    }
+
+    #[test]
+    fn test_response_incomplete() {
+        let raw_response = "250-smtp.example.org\r\n";
+        let res = parse_response(raw_response);
+        match res {
+            Err(nom::Err::Incomplete(_)) => {}
+            _ => panic!("Expected incomplete response, got {:?}", res),
+        }
+    }
+
+    #[test]
+    fn test_response_first_line() {
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: Severity::TransientNegativeCompletion,
+                    category: Category::MailSystem,
+                    detail: Detail::One,
+                },
+                vec![
+                    "me".to_string(),
+                    "8BITMIME".to_string(),
+                    "SIZE 42".to_string(),
+                ],
+            )
+            .first_line(),
+            Some("me")
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: Severity::TransientNegativeCompletion,
+                    category: Category::MailSystem,
+                    detail: Detail::One,
+                },
+                vec![
+                    "me mo".to_string(),
+                    "8BITMIME".to_string(),
+                    "SIZE 42".to_string(),
+                ],
+            )
+            .first_line(),
+            Some("me mo")
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: Severity::TransientNegativeCompletion,
+                    category: Category::MailSystem,
+                    detail: Detail::One,
+                },
+                vec![],
+            )
+            .first_line(),
+            None
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: Severity::TransientNegativeCompletion,
+                    category: Category::MailSystem,
+                    detail: Detail::One,
+                },
+                vec![" ".to_string()],
+            )
+            .first_line(),
+            Some(" ")
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: Severity::TransientNegativeCompletion,
+                    category: Category::MailSystem,
+                    detail: Detail::One,
+                },
+                vec!["  ".to_string()],
+            )
+            .first_line(),
+            Some("  ")
+        );
+        assert_eq!(
+            Response::new(
+                Code {
+                    severity: Severity::TransientNegativeCompletion,
+                    category: Category::MailSystem,
+                    detail: Detail::One,
+                },
+                vec!["".to_string()],
+            )
+            .first_line(),
+            Some("")
+        );
+    }
+}

src/transport/smtp/util.rs

@@ -0,0 +1,48 @@
+//! Utils for string manipulation
+
+use std::fmt::{Display, Formatter, Result as FmtResult};
+
+/// Encode a string as xtext
+#[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct XText<'a>(pub &'a str);
+
+impl<'a> Display for XText<'a> {
+    fn fmt(&self, f: &mut Formatter) -> FmtResult {
+        let mut rest = self.0;
+        while let Some(idx) = rest.find(|c| c < '!' || c == '+' || c == '=') {
+            let (start, end) = rest.split_at(idx);
+            f.write_str(start)?;
+
+            let mut end_iter = end.char_indices();
+            let (_, c) = end_iter.next().expect("char");
+            write!(f, "+{:X}", c as u8)?;
+
+            if let Some((idx, _)) = end_iter.next() {
+                rest = &end[idx..];
+            } else {
+                rest = "";
+            }
+        }
+        f.write_str(rest)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::XText;
+
+    #[test]
+    fn test() {
+        for (input, expect) in [
+            ("bjorn", "bjorn"),
+            ("bjørn", "bjørn"),
+            ("Ø+= ❤️‰", "Ø+2B+3D+20❤️‰"),
+            ("+", "+2B"),
+        ]
+        .iter()
+        {
+            assert_eq!(format!("{}", XText(input)), expect.to_string());
+        }
+    }
+}

src/transport/stub/mod.rs

@@ -0,0 +1,96 @@
+//! The stub transport only logs message envelope and drops the content. It can be useful for
+//! testing purposes.
+//!
+//! #### Stub Transport
+//!
+//! The stub transport returns provided result and drops the content. It can be useful for
+//! testing purposes.
+//!
+//! ```rust
+//! use lettre::{Message, Envelope, Transport, StubTransport};
+//!
+//! let email = Message::builder()
+//!     .from("NoBody <nobody@domain.tld>".parse().unwrap())
+//!     .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+//!     .to("Hei <hei@domain.tld>".parse().unwrap())
+//!     .subject("Happy new year")
+//!     .body("Be happy!")
+//!     .unwrap();
+//!
+//! let mut sender = StubTransport::new_ok();
+//! let result = sender.send(&email);
+//! assert!(result.is_ok());
+//! ```
+
+use crate::{Envelope, Transport};
+use std::{error::Error as StdError, fmt};
+
+#[derive(Debug, Copy, Clone)]
+pub struct Error;
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "stub error")
+    }
+}
+
+impl StdError for Error {
+    fn source(&self) -> Option<&(dyn StdError + 'static)> {
+        None
+    }
+}
+
+/// This transport logs the message envelope and returns the given response
+#[derive(Debug, Clone, Copy)]
+pub struct StubTransport {
+    response: Result<(), Error>,
+}
+
+impl StubTransport {
+    /// Creates aResult new transport that always returns the given response
+    pub fn new(response: Result<(), Error>) -> StubTransport {
+        StubTransport { response }
+    }
+
+    /// Creates a new transport that always returns a success response
+    pub fn new_ok() -> StubTransport {
+        StubTransport { response: Ok(()) }
+    }
+
+    /// Creates a new transport that always returns an error
+    pub fn new_error() -> StubTransport {
+        StubTransport {
+            response: Err(Error),
+        }
+    }
+}
+
+impl Transport for StubTransport {
+    type Ok = ();
+    type Error = Error;
+
+    fn send_raw(&self, _envelope: &Envelope, _email: &[u8]) -> Result<Self::Ok, Self::Error> {
+        self.response
+    }
+}
+
+#[cfg(feature = "async")]
+pub mod r#async {
+    use super::StubTransport;
+    use crate::{r#async::Transport, transport::stub::Error, Envelope};
+    use async_trait::async_trait;
+
+    #[async_trait]
+    impl Transport for StubTransport {
+        type Ok = ();
+        type Error = Error;
+
+        async fn send_raw(
+            &self,
+            _envelope: &Envelope,
+            _email: &[u8],
+        ) -> Result<Self::Ok, Self::Error> {
+            self.response
+        }
+    }
+}

tests/lib.rs

@@ -1,14 +0,0 @@
-// Copyright 2014 Alexis Mousset. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[test]
-
-fn foo() {
-    assert!(true);
-}

tests/transport_file.rs

@@ -0,0 +1,65 @@
+#[cfg(test)]
+#[cfg(feature = "file-transport")]
+mod test {
+    use lettre::{transport::file::FileTransport, Message};
+    use std::{
+        env::temp_dir,
+        fs::{remove_file, File},
+        io::Read,
+    };
+
+    #[test]
+    fn file_transport() {
+        use lettre::Transport;
+        let sender = FileTransport::new(temp_dir());
+        let email = Message::builder()
+            .from("NoBody <nobody@domain.tld>".parse().unwrap())
+            .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+            .to("Hei <hei@domain.tld>".parse().unwrap())
+            .subject("Happy new year")
+            .date("Tue, 15 Nov 1994 08:12:31 GMT".parse().unwrap())
+            .body("Be happy!")
+            .unwrap();
+
+        let result = sender.send(&email);
+        let id = result.unwrap();
+
+        let file = temp_dir().join(format!("{}.json", id));
+        let mut f = File::open(file.clone()).unwrap();
+        let mut buffer = String::new();
+        let _ = f.read_to_string(&mut buffer);
+
+        assert_eq!(
+            buffer,
+            "{\"envelope\":{\"forward_path\":[\"hei@domain.tld\"],\"reverse_path\":\"nobody@domain.tld\"},\"raw_message\":null,\"message\":\"From: NoBody <nobody@domain.tld>\\r\\nReply-To: Yuin <yuin@domain.tld>\\r\\nTo: Hei <hei@domain.tld>\\r\\nSubject: Happy new year\\r\\nDate: Tue, 15 Nov 1994 08:12:31 GMT\\r\\n\\r\\nBe happy!\"}");
+        remove_file(file).unwrap();
+    }
+
+    #[cfg(feature = "async")]
+    #[async_attributes::test]
+    async fn file_transport_async() {
+        use lettre::r#async::Transport;
+        let sender = FileTransport::new(temp_dir());
+        let email = Message::builder()
+            .from("NoBody <nobody@domain.tld>".parse().unwrap())
+            .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+            .to("Hei <hei@domain.tld>".parse().unwrap())
+            .subject("Happy new year")
+            .date("Tue, 15 Nov 1994 08:12:31 GMT".parse().unwrap())
+            .body("Be happy!")
+            .unwrap();
+
+        let result = sender.send(email).await;
+        let id = result.unwrap();
+
+        let file = temp_dir().join(format!("{}.json", id));
+        let mut f = File::open(file.clone()).unwrap();
+        let mut buffer = String::new();
+        let _ = f.read_to_string(&mut buffer);
+
+        assert_eq!(
+            buffer,
+            "{\"envelope\":{\"forward_path\":[\"hei@domain.tld\"],\"reverse_path\":\"nobody@domain.tld\"},\"raw_message\":null,\"message\":\"From: NoBody <nobody@domain.tld>\\r\\nReply-To: Yuin <yuin@domain.tld>\\r\\nTo: Hei <hei@domain.tld>\\r\\nSubject: Happy new year\\r\\nDate: Tue, 15 Nov 1994 08:12:31 GMT\\r\\n\\r\\nBe happy!\"}");
+        remove_file(file).unwrap();
+    }
+}

tests/transport_sendmail.rs

@@ -0,0 +1,40 @@
+#[cfg(test)]
+#[cfg(feature = "sendmail-transport")]
+mod test {
+    use lettre::{transport::sendmail::SendmailTransport, Message};
+
+    #[test]
+    fn sendmail_transport() {
+        use lettre::Transport;
+        let sender = SendmailTransport::new();
+        let email = Message::builder()
+            .from("NoBody <nobody@domain.tld>".parse().unwrap())
+            .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+            .to("Hei <hei@domain.tld>".parse().unwrap())
+            .subject("Happy new year")
+            .body("Be happy!")
+            .unwrap();
+
+        let result = sender.send(&email);
+        println!("{:?}", result);
+        assert!(result.is_ok());
+    }
+
+    #[cfg(feature = "async")]
+    #[async_attributes::test]
+    async fn sendmail_transport_async() {
+        use lettre::r#async::Transport;
+        let sender = SendmailTransport::new();
+        let email = Message::builder()
+            .from("NoBody <nobody@domain.tld>".parse().unwrap())
+            .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+            .to("Hei <hei@domain.tld>".parse().unwrap())
+            .subject("Happy new year")
+            .date("Tue, 15 Nov 1994 08:12:31 GMT".parse().unwrap())
+            .body("Be happy!")
+            .unwrap();
+
+        let result = sender.send(email).await;
+        assert!(result.is_ok());
+    }
+}

tests/transport_smtp.rs

@@ -0,0 +1,21 @@
+#[cfg(test)]
+#[cfg(feature = "smtp-transport")]
+mod test {
+    use lettre::{Message, SmtpTransport, Transport};
+
+    #[test]
+    fn smtp_transport_simple() {
+        let email = Message::builder()
+            .from("NoBody <nobody@domain.tld>".parse().unwrap())
+            .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+            .to("Hei <hei@domain.tld>".parse().unwrap())
+            .subject("Happy new year")
+            .body("Be happy!")
+            .unwrap();
+        SmtpTransport::builder("127.0.0.1")
+            .port(2525)
+            .build()
+            .send(&email)
+            .unwrap();
+    }
+}

tests/transport_smtp_pool.rs

@@ -0,0 +1,62 @@
+#[cfg(all(test, feature = "smtp-transport", feature = "r2d2"))]
+mod test {
+    use lettre::{Envelope, SmtpTransport, Transport};
+    use r2d2::Pool;
+    use std::{sync::mpsc, thread};
+
+    fn envelope() -> Envelope {
+        Envelope::new(
+            Some("user@localhost".parse().unwrap()),
+            vec!["root@localhost".parse().unwrap()],
+        )
+        .unwrap()
+    }
+
+    #[test]
+    fn send_one() {
+        let pool = Pool::builder().max_size(1);
+        let mailer = SmtpTransport::builder("127.0.0.1")
+            .port(2525)
+            .build_with_pool(pool);
+
+        let result = mailer.send_raw(&envelope(), b"test");
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn send_from_thread() {
+        let pool = Pool::builder().max_size(1);
+
+        let mailer = SmtpTransport::builder("127.0.0.1")
+            .port(2525)
+            .build_with_pool(pool);
+
+        let (s1, r1) = mpsc::channel();
+        let (s2, r2) = mpsc::channel();
+
+        let mailer1 = mailer.clone();
+        let t1 = thread::spawn(move || {
+            s1.send(()).unwrap();
+            r2.recv().unwrap();
+            mailer1
+                .send_raw(&envelope(), b"test1")
+                .expect("Send failed from thread 1");
+        });
+
+        let mailer2 = mailer.clone();
+        let t2 = thread::spawn(move || {
+            s2.send(()).unwrap();
+            r1.recv().unwrap();
+            mailer2
+                .send_raw(&envelope(), b"test2")
+                .expect("Send failed from thread 2");
+        });
+
+        t1.join().unwrap();
+        t2.join().unwrap();
+
+        mailer
+            .send_raw(&envelope(), b"test")
+            .expect("Send failed from main thread");
+    }
+}

tests/transport_stub.rs

@@ -0,0 +1,37 @@
+use lettre::{transport::stub::StubTransport, Message};
+
+#[test]
+fn stub_transport() {
+    use lettre::Transport;
+    let sender_ok = StubTransport::new_ok();
+    let sender_ko = StubTransport::new_error();
+    let email = Message::builder()
+        .from("NoBody <nobody@domain.tld>".parse().unwrap())
+        .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+        .to("Hei <hei@domain.tld>".parse().unwrap())
+        .subject("Happy new year")
+        .body("Be happy!")
+        .unwrap();
+
+    sender_ok.send(&email).unwrap();
+    sender_ko.send(&email).unwrap_err();
+}
+
+#[cfg(feature = "async")]
+#[async_attributes::test]
+async fn stub_transport_async() {
+    use lettre::r#async::Transport;
+    let sender_ok = StubTransport::new_ok();
+    let sender_ko = StubTransport::new_error();
+    let email = Message::builder()
+        .from("NoBody <nobody@domain.tld>".parse().unwrap())
+        .reply_to("Yuin <yuin@domain.tld>".parse().unwrap())
+        .to("Hei <hei@domain.tld>".parse().unwrap())
+        .subject("Happy new year")
+        .date("Tue, 15 Nov 1994 08:12:31 GMT".parse().unwrap())
+        .body("Be happy!")
+        .unwrap();
+
+    sender_ok.send(email.clone()).await.unwrap();
+    sender_ko.send(email).await.unwrap_err();
+}