Prepare 0.10.0-alpha.4 release

* Wip CI refactor, Fix cargo hack test --each-feature

* CI Refactor

* Update .github/workflows/test.yml

Co-authored-by: Paolo Barbolini <paolo@paolo565.org>

* Update .github/workflows/test.yml

Co-authored-by: Paolo Barbolini <paolo@paolo565.org>

* Update .github/workflows/test.yml

Co-authored-by: Paolo Barbolini <paolo@paolo565.org>

* Update .github/workflows/test.yml

Co-authored-by: Paolo Barbolini <paolo@paolo565.org>

* Update .github/workflows/test.yml

Co-authored-by: Paolo Barbolini <paolo@paolo565.org>

* Update .github/workflows/test.yml

Co-authored-by: Paolo Barbolini <paolo@paolo565.org>

* Update .github/workflows/test.yml

Co-authored-by: Paolo Barbolini <paolo@paolo565.org>

* Update src/transport/stub/mod.rs

Co-authored-by: Paolo Barbolini <paolo@paolo565.org>

* Adress code review comment

* Update .github/workflows/test.yml

Co-authored-by: Paolo Barbolini <paolo@paolo565.org>

* Adress review comment

* Add necessary sudo command to install postfix

* Set the action name which setup the cache to Setup cache

* Fix delimiter error

* Fix cargo hack test --each-feature

* Remove blanks before no_run

* Remove useless # before imports in doc tests

* Add builder as required feature for all the examples

* Remove blanks before no_run

* Add builder to the test cfg

* Fix building with tokio03-rustls-tls

* Minor improvements

* Use cargo hack only for check in stable

* Improve chache key

Co-authored-by: Paolo Barbolini <paolo@paolo565.org>

Co-authored-by: Paolo Barbolini <paolo@paolo565.org>

.github/workflows/audit.yml

@@ -6,7 +6,7 @@ jobs:
   audit:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - uses: actions-rs/audit-check@v1
         with:
           token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/test.yml

@@ -1,107 +1,124 @@
-name: Continuous integration
+name: CI
 
-on: [push, pull_request]
+on:
+  pull_request:
+  push:
+    branches:
+      - master
 
 jobs:
-  test:
-    name: Test
+  rustfmt:
+    name: rustfmt / stable
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        rust:
-          - stable
-          - beta
-          - 1.45.2
-    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 update
-      - 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-std1
-      - uses: actions-rs/cargo@v1
-        with:
-          command: test
-          args: --features=tokio02
-      - uses: actions-rs/cargo@v1
-        with:
-          command: test
-          args: --features=tokio03
 
-  check:
-    name: Check
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        rust:
-          - stable
-          - beta
-          - 1.45.2
     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
+      - name: Checkout
+        uses: actions/checkout@v2
 
-  fmt:
-    name: Rustfmt
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v1
-      - uses: actions-rs/cargo@v1
-        with:
-          command: fmt
-          args: --all -- --check
+      - name: Install rust
+        run: |
+          rustup update --no-self-update stable
+          rustup component add rustfmt
+
+      - name: cargo fmt
+        run: cargo fmt --all -- --check
 
   clippy:
-    name: Clippy
+    name: clippy / stable
     runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Install rust
+        run: |
+          rustup update --no-self-update stable
+          rustup component add clippy
+
+      - name: Run clippy
+        run: cargo clippy --all-features --all-targets -- -D warnings
+
+  check:
+    name: check / stable
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Setup cache
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-cargo-check
+
+      - name: Install rust
+        run: rustup update --no-self-update stable
+      
+      - name: Install cargo hack
+        run: cargo install cargo-hack --debug
+
+      - name: Check with cargo hack
+        run: cargo hack check --feature-powerset --depth 3
+
+  test:
+    name: test / ${{ matrix.name }}
+    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
+        include:
+          - name: stable
+            rust: stable
+          - name: beta
+            rust: beta
+          - name: 1.45.2
+            rust: 1.45.2
 
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Setup cache
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-cargo-test-${{ matrix.rust }}
+
+      - name: Install rust
+        run: |
+          rustup default ${{ matrix.rust }}
+          rustup update --no-self-update ${{ matrix.rust }}
+
+      - name: Install postfix  
+        run: |
+          DEBIAN_FRONTEND=noninteractive sudo apt-get update
+          DEBIAN_FRONTEND=noninteractive sudo apt-get -y install postfix
+
+      - name: Run SMTP server
+        run: smtp-sink 2525 1000&
+
+      - name: Test with no default features
+        run: cargo test --no-default-features
+
+      - name: Test with default features
+        run: cargo test
+
+      - name: Test with all features
+        run: cargo test --all-features
+  
 #  coverage:
 #    name: Coverage
 #    runs-on: ubuntu-latest
 #    steps:
-#      - uses: actions/checkout@v1
+#      - uses: actions/checkout@v2
 #      - uses: actions-rs/toolchain@v1
 #        with:
 #          toolchain: nightly

Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name = "lettre"
-version = "0.10.0-alpha.3" # remember to update html_root_url and README.md
+# remember to update html_root_url and README.md (Cargo.toml example and deps.rs badge)
+version = "0.10.0-alpha.4"
 description = "Email client"
 readme = "README.md"
 homepage = "https://lettre.rs"
@@ -35,7 +36,7 @@ serde = { version = "1", optional = true, features = ["derive"] }
 serde_json = { version = "1", optional = true }
 
 # smtp
-nom = { version = "5", optional = true }
+nom = { version = "6", default-features = false, features = ["alloc"], optional = true }
 r2d2 = { version = "0.8", optional = true } # feature
 hostname = { version = "0.3", optional = true } # feature
 
@@ -46,8 +47,8 @@ webpki = { version = "0.21", optional = true }
 webpki-roots = { version = "0.20", optional = true }
 
 # async
-futures-io = { version = "0.3", optional = true }
-futures-util = { version = "0.3", features = ["io"], optional = true }
+futures-io = { version = "0.3.7", optional = true }
+futures-util = { version = "0.3.7", features = ["io"], optional = true }
 
 ## async-std
 async-attributes = { version = "1.1", optional = true }
@@ -101,33 +102,33 @@ rustdoc-args = ["--cfg", "docsrs"]
 
 [[example]]
 name = "smtp"
-required-features = ["smtp-transport"]
+required-features = ["smtp-transport", "builder"]
 
 [[example]]
 name = "smtp_tls"
-required-features = ["smtp-transport", "native-tls"]
+required-features = ["smtp-transport", "native-tls", "builder"]
 
 [[example]]
 name = "smtp_starttls"
-required-features = ["smtp-transport", "native-tls"]
+required-features = ["smtp-transport", "native-tls", "builder"]
 
 [[example]]
 name = "smtp_selfsigned"
-required-features = ["smtp-transport", "native-tls"]
+required-features = ["smtp-transport", "native-tls", "builder"]
 
 [[example]]
 name = "tokio02_smtp_tls"
-required-features = ["smtp-transport", "tokio02", "tokio02-native-tls"]
+required-features = ["smtp-transport", "tokio02", "tokio02-native-tls", "builder"]
 
 [[example]]
 name = "tokio02_smtp_starttls"
-required-features = ["smtp-transport", "tokio02", "tokio02-native-tls"]
+required-features = ["smtp-transport", "tokio02", "tokio02-native-tls", "builder"]
 
 [[example]]
 name = "tokio03_smtp_tls"
-required-features = ["smtp-transport", "tokio03", "tokio03-native-tls"]
+required-features = ["smtp-transport", "tokio03", "tokio03-native-tls", "builder"]
 
 [[example]]
 name = "tokio03_smtp_starttls"
-required-features = ["smtp-transport", "tokio03", "tokio03-native-tls"]
+required-features = ["smtp-transport", "tokio03", "tokio03-native-tls", "builder"]
 

README.md

@@ -27,6 +27,13 @@
   </a>
 </div>
 
+<div align="center">
+  <a href="https://deps.rs/crate/lettre/0.10.0-alpha.4">
+    <img src="https://deps.rs/crate/lettre/0.10.0-alpha.4/status.svg"
+      alt="dependency status" />
+  </a>
+</div>
+
 ---
 
 **NOTE**: this readme refers to the 0.10 version of lettre, which is
@@ -59,7 +66,7 @@ To use this library, add the following to your `Cargo.toml`:
 
 ```toml
 [dependencies]
-lettre = "0.10.0-alpha.3"
+lettre = "0.10.0-alpha.4"
 ```
 
 ```rust,no_run

examples/README.md

@@ -0,0 +1,16 @@
+# Lettre Examples
+
+This folder contains examples showing how to use lettre in your own projects.
+
+## Examples
+- [smtp.rs] - Send an email using a local SMTP daemon on port 25 as a relay.
+- [smtp_tls.rs] - Send an email over SMTP encrypted with TLS and authenticating with username and password.
+- [smtp_starttls.rs] - Send an email over SMTP with STARTTLS and authenticating with username and password.
+- [smtp_selfsigned.rs] - Send an email over SMTP encrypted with TLS using a self-signed certificate and authenticating with username and password.
+- The [smtp_tls.rs] and [smtp_starttls.rs] examples also feature `async`hronous implementations powered by [Tokio](https://tokio.rs/).
+  These files are prefixed with `tokio02_` or `tokio03_`.
+
+[smtp.rs]: ./smtp.rs
+[smtp_tls.rs]: ./smtp_tls.rs
+[smtp_starttls.rs]: ./smtp_starttls.rs
+[smtp_selfsigned.rs]: ./smtp_selfsigned.rs

src/address/envelope.rs

@@ -32,10 +32,14 @@ impl Envelope {
     /// # use lettre::Address;
     /// # use lettre::address::Envelope;
     ///
-    /// let sender = Address::from_str("from@email.com").unwrap();
-    /// let recipients = vec![Address::from_str("to@email.com").unwrap()];
+    /// # use std::error::Error;
+    /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// let sender = Address::from_str("from@email.com")?;
+    /// let recipients = vec![Address::from_str("to@email.com")?];
     ///
     /// let envelope = Envelope::new(Some(sender), recipients);
+    /// # Ok(())
+    /// # }
     /// ```
     ///
     /// # Errors
@@ -60,11 +64,15 @@ impl Envelope {
     /// # use lettre::Address;
     /// # use lettre::address::Envelope;
     ///
-    /// let sender = Address::from_str("from@email.com").unwrap();
-    /// let recipients = vec![Address::from_str("to@email.com").unwrap()];
+    /// # use std::error::Error;
+    /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// let sender = Address::from_str("from@email.com")?;
+    /// let recipients = vec![Address::from_str("to@email.com")?];
     ///
-    /// let envelope = Envelope::new(Some(sender), recipients.clone()).unwrap();
+    /// let envelope = Envelope::new(Some(sender), recipients.clone())?;
     /// assert_eq!(envelope.to(), recipients.as_slice());
+    /// # Ok(())
+    /// # }
     /// ```
     pub fn to(&self) -> &[Address] {
         self.forward_path.as_slice()
@@ -79,14 +87,18 @@ impl Envelope {
     /// # use lettre::Address;
     /// # use lettre::address::Envelope;
     ///
-    /// let sender = Address::from_str("from@email.com").unwrap();
-    /// let recipients = vec![Address::from_str("to@email.com").unwrap()];
+    /// # use std::error::Error;
+    /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// let sender = Address::from_str("from@email.com")?;
+    /// let recipients = vec![Address::from_str("to@email.com")?];
     ///
-    /// let envelope = Envelope::new(Some(sender), recipients.clone()).unwrap();
+    /// let envelope = Envelope::new(Some(sender), recipients.clone())?;
     /// assert!(envelope.from().is_some());
     ///
-    /// let senderless = Envelope::new(None, recipients.clone()).unwrap();
+    /// let senderless = Envelope::new(None, recipients.clone())?;
     /// assert!(senderless.from().is_none());
+    /// # Ok(())
+    /// # }
     /// ```
     pub fn from(&self) -> Option<&Address> {
         self.reverse_path.as_ref()

src/address/types.rs

@@ -24,7 +24,11 @@ use std::{
 ///
 /// ```
 /// # use lettre::Address;
-/// let address = Address::new("example", "email.com").unwrap();
+/// # use std::error::Error;
+/// # fn main() -> Result<(), Box<dyn Error>> {
+/// let address = Address::new("example", "email.com")?;
+/// # Ok(())
+/// # }
 /// ```
 ///
 /// You can also create an `Address` from a string literal by parsing it:
@@ -32,7 +36,11 @@ use std::{
 /// ```
 /// use std::str::FromStr;
 /// # use lettre::Address;
-/// let address = Address::from_str("example@email.com").unwrap();
+/// # use std::error::Error;
+/// # fn main() -> Result<(), Box<dyn Error>> {
+/// let address = Address::from_str("example@email.com")?;
+/// # Ok(())
+/// # }
 /// ```
 #[derive(Debug, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]
 pub struct Address {
@@ -86,9 +94,13 @@ impl Address {
     /// ```
     /// use lettre::Address;
     ///
-    /// let address = Address::new("example", "email.com").unwrap();
-    /// let expected: Address = "example@email.com".parse().unwrap();
+    /// # use std::error::Error;
+    /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// let address = Address::new("example", "email.com")?;
+    /// let expected: Address = "example@email.com".parse()?;
     /// assert_eq!(expected, address);
+    /// # Ok(())
+    /// # }
     /// ```
     pub fn new<U: AsRef<str>, D: AsRef<str>>(user: U, domain: D) -> Result<Self, AddressError> {
         (user, domain).try_into()
@@ -101,8 +113,12 @@ impl Address {
     /// ```
     /// use lettre::Address;
     ///
-    /// let address = Address::new("example", "email.com").unwrap();
+    /// # use std::error::Error;
+    /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// let address = Address::new("example", "email.com")?;
     /// assert_eq!("example", address.user());
+    /// # Ok(())
+    /// # }
     /// ```
     pub fn user(&self) -> &str {
         &self.serialized[..self.at_start]
@@ -115,8 +131,12 @@ impl Address {
     /// ```
     /// use lettre::Address;
     ///
-    /// let address = Address::new("example", "email.com").unwrap();
+    /// # use std::error::Error;
+    /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// let address = Address::new("example", "email.com")?;
     /// assert_eq!("email.com", address.domain());
+    /// # Ok(())
+    /// # }
     /// ```
     pub fn domain(&self) -> &str {
         &self.serialized[self.at_start + 1..]

src/lib.rs

@@ -27,7 +27,7 @@
 //! * **serde**: Serialization/Deserialization of entities
 //! * **hostname**: Ability to try to use actual hostname in SMTP transaction
 
-#![doc(html_root_url = "https://docs.rs/crate/lettre/0.10.0-alpha.3")]
+#![doc(html_root_url = "https://docs.rs/crate/lettre/0.10.0-alpha.4")]
 #![doc(html_favicon_url = "https://lettre.rs/favicon.ico")]
 #![doc(html_logo_url = "https://avatars0.githubusercontent.com/u/15113230?v=4")]
 #![forbid(unsafe_code)]
@@ -163,6 +163,7 @@ pub trait Tokio03Transport {
 }
 
 #[cfg(test)]
+#[cfg(feature = "builder")]
 mod test {
     use super::*;
     use crate::message::{header, Mailbox, Mailboxes};

src/message/mailbox/types.rs

@@ -21,15 +21,23 @@ use std::{
 ///
 /// ```
 /// # use lettre::{Address, message::Mailbox};
-/// let address = Address::new("example", "email.com").unwrap();
+/// # use std::error::Error;
+/// # fn main() -> Result<(), Box<dyn Error>> {
+/// let address = Address::new("example", "email.com")?;
 /// let mailbox = Mailbox::new(None, address);
+/// # Ok(())
+/// # }
 /// ```
 ///
 /// You can also create one from a string literal:
 ///
 /// ```
 /// # use lettre::message::Mailbox;
-/// let mailbox: Mailbox = "John Smith <example@email.com>".parse().unwrap();
+/// # use std::error::Error;
+/// # fn main() -> Result<(), Box<dyn Error>> {
+/// let mailbox: Mailbox = "John Smith <example@email.com>".parse()?;
+/// # Ok(())
+/// # }
 /// ```
 #[derive(Debug, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]
 pub struct Mailbox {
@@ -48,8 +56,12 @@ impl Mailbox {
     /// ```
     /// use lettre::{Address, message::Mailbox};
     ///
-    /// let address = Address::new("example", "email.com").unwrap();
+    /// # use std::error::Error;
+    /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// let address = Address::new("example", "email.com")?;
     /// let mailbox = Mailbox::new(None, address);
+    /// # Ok(())
+    /// # }
     /// ```
     pub fn new(name: Option<String>, email: Address) -> Self {
         Mailbox { name, email }
@@ -153,8 +165,12 @@ impl Mailboxes {
     /// ```
     /// use lettre::{Address, message::{Mailbox, Mailboxes}};
     ///
-    /// let address = Address::new("example", "email.com").unwrap();
+    /// # use std::error::Error;
+    /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// let address = Address::new("example", "email.com")?;
     /// let mut mailboxes = Mailboxes::new().with(Mailbox::new(None, address));
+    /// # Ok(())
+    /// # }
     /// ```
     pub fn with(mut self, mbox: Mailbox) -> Self {
         self.0.push(mbox);
@@ -168,9 +184,13 @@ impl Mailboxes {
     /// ```
     /// use lettre::{Address, message::{Mailbox, Mailboxes}};
     ///
-    /// let address = Address::new("example", "email.com").unwrap();
+    /// # use std::error::Error;
+    /// # fn main() -> Result<(), Box<dyn Error>> {
+    /// let address = Address::new("example", "email.com")?;
     /// let mut mailboxes = Mailboxes::new();
     /// mailboxes.push(Mailbox::new(None, address));
+    /// # Ok(())
+    /// # }
     /// ```
     pub fn push(&mut self, mbox: Mailbox) {
         self.0.push(mbox);
@@ -183,14 +203,18 @@ impl Mailboxes {
     /// ```
     /// use lettre::{Address, message::{Mailbox, Mailboxes}};
     ///
+    /// # use std::error::Error;
+    /// # fn main() -> Result<(), Box<dyn Error>> {
     /// let empty = Mailboxes::new();
     /// assert!(empty.into_single().is_none());
     ///
     /// let mut mailboxes = Mailboxes::new();
-    /// let address = Address::new("example", "email.com").unwrap();
+    /// let address = Address::new("example", "email.com")?;
     ///
     /// mailboxes.push(Mailbox::new(None, address));
     /// assert!(mailboxes.into_single().is_some());
+    /// # Ok(())
+    /// # }
     /// ```
     pub fn into_single(self) -> Option<Mailbox> {
         self.into()
@@ -203,12 +227,14 @@ impl Mailboxes {
     /// ```
     /// use lettre::{Address, message::{Mailbox, Mailboxes}};
     ///
+    /// # use std::error::Error;
+    /// # fn main() -> Result<(), Box<dyn Error>> {
     /// let mut mailboxes = Mailboxes::new();
     ///
-    /// let address = Address::new("example", "email.com").unwrap();
+    /// let address = Address::new("example", "email.com")?;
     /// mailboxes.push(Mailbox::new(None, address));
     ///
-    /// let address = Address::new("example", "email.com").unwrap();
+    /// let address = Address::new("example", "email.com")?;
     /// mailboxes.push(Mailbox::new(None, address));
     ///
     /// let mut iter = mailboxes.iter();
@@ -217,6 +243,8 @@ impl Mailboxes {
     /// assert!(iter.next().is_some());
     ///
     /// assert!(iter.next().is_none());
+    /// # Ok(())
+    /// # }
     /// ```
     pub fn iter(&self) -> Iter<'_, Mailbox> {
         self.0.iter()

src/message/mimebody.rs

@@ -90,10 +90,14 @@ impl Default for SinglePartBuilder {
 /// ```
 /// use lettre::message::{SinglePart, header};
 ///
+/// # use std::error::Error;
+/// # fn main() -> Result<(), Box<dyn Error>> {
 /// let part = SinglePart::builder()
-///      .header(header::ContentType("text/plain; charset=utf8".parse().unwrap()))
+///      .header(header::ContentType("text/plain; charset=utf8".parse()?))
 ///      .header(header::ContentTransferEncoding::Binary)
 ///      .body("Текст письма в уникоде");
+/// # Ok(())
+/// # }
 /// ```
 ///
 #[derive(Debug, Clone)]

src/message/mod.rs

@@ -15,13 +15,16 @@
 //! ```rust
 //! use lettre::message::Message;
 //!
+//! # use std::error::Error;
+//! # fn main() -> Result<(), Box<dyn Error>> {
 //! 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())
+//!     .from("NoBody <nobody@domain.tld>".parse()?)
+//!     .reply_to("Yuin <yuin@domain.tld>".parse()?)
+//!     .to("Hei <hei@domain.tld>".parse()?)
 //!     .subject("Happy new year")
-//!     .body("Be happy!")
-//!     .unwrap();
+//!     .body("Be happy!")?;
+//! # Ok(())
+//! # }
 //! ```
 //!
 //! Will produce:
@@ -46,19 +49,22 @@
 //! ```rust
 //! use lettre::message::{header, Message, SinglePart, Part};
 //!
+//! # use std::error::Error;
+//! # fn main() -> Result<(), Box<dyn Error>> {
 //! 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())
+//!     .from("NoBody <nobody@domain.tld>".parse()?)
+//!     .reply_to("Yuin <yuin@domain.tld>".parse()?)
+//!     .to("Hei <hei@domain.tld>".parse()?)
 //!     .subject("Happy new year")
 //!     .singlepart(
 //!         SinglePart::builder()
 //!             .header(header::ContentType(
-//!                 "text/plain; charset=utf8".parse().unwrap(),
+//!                 "text/plain; charset=utf8".parse()?,
 //!             )).header(header::ContentTransferEncoding::QuotedPrintable)
 //!             .body("Привет, мир!"),
-//!     )
-//!     .unwrap();
+//!     )?;
+//! # Ok(())
+//! # }
 //! ```
 //!
 //! The body will be encoded using selected `Content-Transfer-Encoding`.
@@ -83,10 +89,12 @@
 //! ```rust
 //! use lettre::message::{header, Message, MultiPart, SinglePart, Part};
 //!
+//! # use std::error::Error;
+//! # fn main() -> Result<(), Box<dyn Error>> {
 //! 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())
+//!     .from("NoBody <nobody@domain.tld>".parse()?)
+//!     .reply_to("Yuin <yuin@domain.tld>".parse()?)
+//!     .to("Hei <hei@domain.tld>".parse()?)
 //!     .subject("Happy new year")
 //!     .multipart(
 //!         MultiPart::mixed()
@@ -94,19 +102,19 @@
 //!             MultiPart::alternative()
 //!             .singlepart(
 //!                 SinglePart::quoted_printable()
-//!                 .header(header::ContentType("text/plain; charset=utf8".parse().unwrap()))
+//!                 .header(header::ContentType("text/plain; charset=utf8".parse()?))
 //!                 .body("Привет, мир!")
 //!             )
 //!             .multipart(
 //!                MultiPart::related()
 //!                 .singlepart(
 //!                     SinglePart::eight_bit()
-//!                     .header(header::ContentType("text/html; charset=utf8".parse().unwrap()))
+//!                     .header(header::ContentType("text/html; charset=utf8".parse()?))
 //!                     .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::ContentType("image/png".parse()?))
 //!                     .header(header::ContentDisposition {
 //!                         disposition: header::DispositionType::Inline,
 //!                         parameters: vec![],
@@ -117,7 +125,7 @@
 //!         )
 //!         .singlepart(
 //!             SinglePart::seven_bit()
-//!             .header(header::ContentType("text/plain; charset=utf8".parse().unwrap()))
+//!             .header(header::ContentType("text/plain; charset=utf8".parse()?))
 //!             .header(header::ContentDisposition {
 //!                 disposition: header::DispositionType::Attachment,
 //!                 parameters: vec![
@@ -129,7 +137,9 @@
 //!             })
 //!             .body("int main() { return 0; }")
 //!         )
-//!     ).unwrap();
+//!     )?;
+//! # Ok(())
+//! # }
 //! ```
 //!
 //! ```sh

src/transport/file/mod.rs

@@ -5,66 +5,79 @@
 //! ## Sync example
 //!
 //! ```rust
+//! # use std::error::Error;
+//!
+//! # #[cfg(all(feature = "file-transport", feature = "builder"))]
+//! # fn main() -> Result<(), Box<dyn Error>> {
 //! use std::env::temp_dir;
 //! use lettre::{Transport, 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())
+//!     .from("NoBody <nobody@domain.tld>".parse()?)
+//!     .reply_to("Yuin <yuin@domain.tld>".parse()?)
+//!     .to("Hei <hei@domain.tld>".parse()?)
 //!     .subject("Happy new year")
-//!     .body("Be happy!")
-//!     .unwrap();
+//!     .body("Be happy!")?;
 //!
 //! let result = sender.send(&email);
 //! assert!(result.is_ok());
+//! # Ok(())
+//! # }
+//!
+//! # #[cfg(not(all(feature = "file-transport", feature = "builder")))]
+//! # fn main() {}
 //! ```
 //!
+//!
 //! ## Async tokio 0.2
 //!
-//! ```rust
-//! # #[cfg(feature = "tokio02")]
-//! # async fn run() {
+//! ```rust,no_run
+//! # use std::error::Error;
+//!
+//! # #[cfg(all(feature = "tokio02", feature = "file-transport", feature = "builder"))]
+//! # async fn run() -> Result<(), Box<dyn Error>> {
 //! use std::env::temp_dir;
 //! use lettre::{Tokio02Transport, 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())
+//!     .from("NoBody <nobody@domain.tld>".parse()?)
+//!     .reply_to("Yuin <yuin@domain.tld>".parse()?)
+//!     .to("Hei <hei@domain.tld>".parse()?)
 //!     .subject("Happy new year")
-//!     .body("Be happy!")
-//!     .unwrap();
+//!     .body("Be happy!")?;
 //!
 //! let result = sender.send(email).await;
 //! assert!(result.is_ok());
+//! # Ok(())
 //! # }
 //! ```
 //!
 //! ## Async async-std 1.x
 //!
-//! ```rust
-//! # #[cfg(feature = "async-std1")]
-//! # async fn run() {
+//! ```rust,no_run
+//! # use std::error::Error;
+//!
+//! # #[cfg(all(feature = "async-std1", feature = "file-transport", feature = "builder"))]
+//! # async fn run() -> Result<(), Box<dyn Error>> {
 //! use std::env::temp_dir;
 //! use lettre::{AsyncStd1Transport, 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())
+//!     .from("NoBody <nobody@domain.tld>".parse()?)
+//!     .reply_to("Yuin <yuin@domain.tld>".parse()?)
+//!     .to("Hei <hei@domain.tld>".parse()?)
 //!     .subject("Happy new year")
-//!     .body("Be happy!")
-//!     .unwrap();
+//!     .body("Be happy!")?;
 //!
 //! let result = sender.send(email).await;
 //! assert!(result.is_ok());
+//! # Ok(())
 //! # }
 //! ```
 //!

src/transport/sendmail/mod.rs

@@ -3,60 +3,72 @@
 //! ## Sync example
 //!
 //! ```rust
-//! use lettre::{Message, Transport, SendmailTransport};
+//! # use std::error::Error;
+//!
+//! # #[cfg(all(feature = "sendmail-transport", feature = "builder"))]
+//! # fn main() -> Result<(), Box<dyn Error>> {
+//! # use lettre::{Message, 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())
+//!     .from("NoBody <nobody@domain.tld>".parse()?)
+//!     .reply_to("Yuin <yuin@domain.tld>".parse()?)
+//!     .to("Hei <hei@domain.tld>".parse()?)
 //!     .subject("Happy new year")
-//!     .body("Be happy!")
-//!     .unwrap();
+//!     .body("Be happy!")?;
 //!
 //! let sender = SendmailTransport::new();
 //! let result = sender.send(&email);
 //! assert!(result.is_ok());
+//! # Ok(())
+//! # }
+//!
+//! # #[cfg(not(all(feature = "sendmail-transport", feature = "builder")))]
+//! # fn main() {}
 //! ```
 //!
 //! ## Async tokio 0.2 example
 //!
-//! ```rust
-//! # #[cfg(feature = "tokio02")]
-//! # async fn run() {
+//! ```rust,no_run
+//! # use std::error::Error;
+//!
+//! # #[cfg(all(feature = "tokio02", feature = "sendmail-transport", feature = "builder"))]
+//! # async fn run() -> Result<(), Box<dyn Error>> {
 //! use lettre::{Message, Tokio02Transport, 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())
+//!     .from("NoBody <nobody@domain.tld>".parse()?)
+//!     .reply_to("Yuin <yuin@domain.tld>".parse()?)
+//!     .to("Hei <hei@domain.tld>".parse()?)
 //!     .subject("Happy new year")
-//!     .body("Be happy!")
-//!     .unwrap();
+//!     .body("Be happy!")?;
 //!
 //! let sender = SendmailTransport::new();
 //! let result = sender.send(email).await;
 //! assert!(result.is_ok());
+//! # Ok(())
 //! # }
 //! ```
 //!
 //! ## Async async-std 1.x example
 //!
-//!```rust
-//! # #[cfg(feature = "async-std1")]
-//! # async fn run() {
+//!```rust,no_run
+//! # use std::error::Error;
+//!
+//! # #[cfg(all(feature = "async-std1", feature = "sendmail-transport", feature = "builder"))]
+//! # async fn run() -> Result<(), Box<dyn Error>> {
 //! use lettre::{Message, AsyncStd1Transport, 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())
+//!     .from("NoBody <nobody@domain.tld>".parse()?)
+//!     .reply_to("Yuin <yuin@domain.tld>".parse()?)
+//!     .to("Hei <hei@domain.tld>".parse()?)
 //!     .subject("Happy new year")
-//!     .body("Be happy!")
-//!     .unwrap();
+//!     .body("Be happy!")?;
 //!
 //! let sender = SendmailTransport::new();
 //! let result = sender.send(email).await;
 //! assert!(result.is_ok());
+//! # Ok(())
 //! # }
 //! ```
 
@@ -105,12 +117,15 @@ impl SendmailTransport {
 
     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("\"\""))
+        c.arg("-i");
+        if let Some(from) = envelope.from() {
+            c.arg("-f").arg(from);
+        }
+        c.arg("--")
             .args(envelope.to())
             .stdin(Stdio::piped())
-            .stdout(Stdio::piped());
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped());
         c
     }
 
@@ -120,12 +135,15 @@ impl SendmailTransport {
 
         let mut c = Command::new(&self.command);
         c.kill_on_drop(true);
-        c.arg("-i")
-            .arg("-f")
-            .arg(envelope.from().map(|f| f.as_ref()).unwrap_or("\"\""))
+        c.arg("-i");
+        if let Some(from) = envelope.from() {
+            c.arg("-f").arg(from);
+        }
+        c.arg("--")
             .args(envelope.to())
             .stdin(Stdio::piped())
-            .stdout(Stdio::piped());
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped());
         c
     }
 
@@ -135,12 +153,15 @@ impl SendmailTransport {
 
         let mut c = Command::new(&self.command);
         c.kill_on_drop(true);
-        c.arg("-i")
-            .arg("-f")
-            .arg(envelope.from().map(|f| f.as_ref()).unwrap_or("\"\""))
+        c.arg("-i");
+        if let Some(from) = envelope.from() {
+            c.arg("-f").arg(from);
+        }
+        c.arg("--")
             .args(envelope.to())
             .stdin(Stdio::piped())
-            .stdout(Stdio::piped());
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped());
         c
     }
 }

src/transport/smtp/client/async_connection.rs

@@ -268,11 +268,11 @@ impl AsyncSmtpConnection {
                     return Err(response.into());
                 }
                 Err(nom::Err::Failure(e)) => {
-                    return Err(Error::Parsing(e.1));
+                    return Err(Error::Parsing(e.code));
                 }
                 Err(nom::Err::Incomplete(_)) => { /* read more */ }
                 Err(nom::Err::Error(e)) => {
-                    return Err(Error::Parsing(e.1));
+                    return Err(Error::Parsing(e.code));
                 }
             }
         }

src/transport/smtp/client/async_net.rs

@@ -1,4 +1,4 @@
-#[cfg(feature = "tokio02-rustls-tls")]
+#[cfg(any(feature = "tokio02-rustls-tls", feature = "tokio03-rustls-tls"))]
 use std::sync::Arc;
 use std::{
     net::{Shutdown, SocketAddr},

src/transport/smtp/client/connection.rs

@@ -253,11 +253,11 @@ impl SmtpConnection {
                     return Err(response.into());
                 }
                 Err(nom::Err::Failure(e)) => {
-                    return Err(Error::Parsing(e.1));
+                    return Err(Error::Parsing(e.code));
                 }
                 Err(nom::Err::Incomplete(_)) => { /* read more */ }
                 Err(nom::Err::Error(e)) => {
-                    return Err(Error::Parsing(e.1));
+                    return Err(Error::Parsing(e.code));
                 }
             }
         }

src/transport/smtp/client/mod.rs

@@ -3,21 +3,24 @@
 //! `SmtpConnection` allows manually sending SMTP commands.
 //!
 //! ```rust,no_run
+//! # use std::error::Error;
+//!
 //! # #[cfg(feature = "smtp-transport")]
-//! # {
+//! # fn main() -> Result<(), Box<dyn Error>> {
 //! use lettre::transport::smtp::{SMTP_PORT, extension::ClientId, commands::*, client::SmtpConnection};
 //!
 //! let hello = ClientId::Domain("my_hostname".to_string());
-//! let mut client = SmtpConnection::connect(&("localhost", SMTP_PORT), None, &hello, None).unwrap();
+//! let mut client = SmtpConnection::connect(&("localhost", SMTP_PORT), None, &hello, None)?;
 //! client.command(
-//!         Mail::new(Some("user@example.com".parse().unwrap()), vec![])
-//!     ).unwrap();
+//!         Mail::new(Some("user@example.com".parse()?), vec![])
+//!     )?;
 //! 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();
+//!         Rcpt::new("user@example.org".parse()?, vec![])
+//!       )?;
+//! client.command(Data)?;
+//! client.message("Test email".as_bytes())?;
+//! client.command(Quit)?;
+//! # Ok(())
 //! # }
 //! ```
 

src/transport/smtp/error.rs

@@ -109,12 +109,12 @@ impl From<native_tls::Error> for Error {
     }
 }
 
-impl From<nom::Err<(&str, nom::error::ErrorKind)>> for Error {
-    fn from(err: nom::Err<(&str, nom::error::ErrorKind)>) -> Error {
+impl From<nom::Err<nom::error::Error<&str>>> for Error {
+    fn from(err: nom::Err<nom::error::Error<&str>>) -> Error {
         Parsing(match err {
             nom::Err::Incomplete(_) => nom::error::ErrorKind::Complete,
-            nom::Err::Failure((_, k)) => k,
-            nom::Err::Error((_, k)) => k,
+            nom::Err::Failure(e) => e.code,
+            nom::Err::Error(e) => e.code,
         })
     }
 }

src/transport/smtp/mod.rs

@@ -31,17 +31,16 @@
 //! This is the most basic example of usage:
 //!
 //! ```rust,no_run
-//! # #[cfg(any(feature = "native-tls", feature = "rustls-tls"))]
-//! # {
+//! # #[cfg(all(feature = "builder", any(feature = "native-tls", feature = "rustls-tls")))]
+//! # fn test() -> Result<(), Box<dyn std::error::Error>> {
 //! 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())
+//!     .from("NoBody <nobody@domain.tld>".parse()?)
+//!     .reply_to("Yuin <yuin@domain.tld>".parse()?)
+//!     .to("Hei <hei@domain.tld>".parse()?)
 //!     .subject("Happy new year")
-//!     .body("Be happy!")
-//!     .unwrap();
+//!     .body("Be happy!")?;
 //!
 //! // Create TLS transport on port 465
 //! let sender = SmtpTransport::relay("smtp.example.com")
@@ -50,6 +49,7 @@
 //! // Send the email via remote relay
 //! let result = sender.send(&email);
 //! assert!(result.is_ok());
+//! # Ok(())
 //! # }
 //! ```
 
@@ -64,24 +64,24 @@
 //!
 //! let email_1 = Email::new(
 //!     Envelope::new(
-//!         Some(EmailAddress::new("user@localhost".to_string()).unwrap()),
-//!         vec![EmailAddress::new("root@localhost".to_string()).unwrap()],
-//!     ).unwrap(),
+//!         Some(EmailAddress::new("user@localhost".to_string())?),
+//!         vec![EmailAddress::new("root@localhost".to_string())?],
+//!     )?,
 //!     "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(),
+//!         Some(EmailAddress::new("user@localhost".to_string())?),
+//!         vec![EmailAddress::new("root@localhost".to_string())?],
+//!     )?,
 //!     "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()
+//! let mut mailer = SmtpClient::new_simple("server.tld")?
 //!    // Set the name sent during EHLO/HELO, default is `localhost`
 //!    .hello_name(ClientId::Domain("my.hostname.tld".to_string()))
 //!    // Add credentials for authentication
@@ -120,9 +120,9 @@
 //!
 //!     let email = Email::new(
 //!         Envelope::new(
-//!             Some(EmailAddress::new("user@localhost".to_string()).unwrap()),
-//!             vec![EmailAddress::new("root@localhost".to_string()).unwrap()],
-//!         ).unwrap(),
+//!             Some(EmailAddress::new("user@localhost".to_string())?),
+//!             vec![EmailAddress::new("root@localhost".to_string())?],
+//!         )?,
 //!         "message_id".to_string(),
 //!         "Hello world".to_string().into_bytes(),
 //!     );
@@ -132,12 +132,12 @@
 //!     let tls_parameters =
 //!         ClientTlsParameters::new(
 //!             "smtp.example.com".to_string(),
-//!             tls_builder.build().unwrap()
+//!             tls_builder.build()?
 //!         );
 //!
 //!     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()
@@ -164,6 +164,7 @@ pub use self::async_transport::{
 };
 #[cfg(feature = "r2d2")]
 pub use self::pool::PoolConfig;
+#[cfg(feature = "r2d2")]
 pub(crate) use self::transport::SmtpClient;
 pub use self::{
     error::Error,

src/transport/smtp/response.rs

@@ -238,7 +238,10 @@ pub(crate) fn parse_response(i: &str) -> IResult<&str, Response> {
 
     // Check that all codes are equal.
     if !lines.iter().all(|&(code, _, _)| code == last_code) {
-        return Err(nom::Err::Failure(("", nom::error::ErrorKind::Not)));
+        return Err(nom::Err::Failure(nom::error::Error::new(
+            "",
+            nom::error::ErrorKind::Not,
+        )));
     }
 
     // Extract text from lines, and append last line.

src/transport/stub/mod.rs

@@ -7,20 +7,26 @@
 //! testing purposes.
 //!
 //! ```rust
+//! # #[cfg(feature = "builder")]
+//! # {
 //! use lettre::{Message, Transport};
 //! use lettre::transport::stub::StubTransport;
 //!
+//! # use std::error::Error;
+//! # fn main() -> Result<(), Box<dyn 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())
+//!     .from("NoBody <nobody@domain.tld>".parse()?)
+//!     .reply_to("Yuin <yuin@domain.tld>".parse()?)
+//!     .to("Hei <hei@domain.tld>".parse()?)
 //!     .subject("Happy new year")
-//!     .body("Be happy!")
-//!     .unwrap();
+//!     .body("Be happy!")?;
 //!
 //! let mut sender = StubTransport::new_ok();
 //! let result = sender.send(&email);
 //! assert!(result.is_ok());
+//! # Ok(())
+//! # }
+//! # }
 //! ```
 
 use crate::address::Envelope;

tests/transport_file.rs

@@ -1,5 +1,5 @@
 #[cfg(test)]
-#[cfg(feature = "file-transport")]
+#[cfg(all(feature = "file-transport", feature = "builder"))]
 mod test {
     use lettre::{transport::file::FileTransport, Message};
     use std::{

tests/transport_sendmail.rs

@@ -1,5 +1,5 @@
 #[cfg(test)]
-#[cfg(feature = "sendmail-transport")]
+#[cfg(all(feature = "sendmail-transport", feature = "builder"))]
 mod test {
     use lettre::{transport::sendmail::SendmailTransport, Message};
 

tests/transport_smtp.rs

@@ -1,5 +1,5 @@
 #[cfg(test)]
-#[cfg(feature = "smtp-transport")]
+#[cfg(all(feature = "smtp-transport", feature = "builder"))]
 mod test {
     use lettre::{Message, SmtpTransport, Transport};
 

tests/transport_stub.rs

@@ -1,61 +1,65 @@
-use lettre::{transport::stub::StubTransport, Message};
+#[cfg(test)]
+#[cfg(feature = "builder")]
+mod test {
+    use lettre::{transport::stub::StubTransport, Message};
 
-#[cfg(feature = "tokio02")]
-use tokio02_crate as tokio;
+    #[cfg(feature = "tokio02")]
+    use tokio02_crate as tokio;
 
-#[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();
+    #[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-std1")]
-#[async_attributes::test]
-async fn stub_transport_asyncstd1() {
-    use lettre::AsyncStd1Transport;
-
-    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();
-}
-
-#[cfg(feature = "tokio02")]
-#[tokio::test]
-async fn stub_transport_tokio02() {
-    use lettre::Tokio02Transport;
-
-    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();
+        sender_ok.send(&email).unwrap();
+        sender_ko.send(&email).unwrap_err();
+    }
+
+    #[cfg(feature = "async-std1")]
+    #[async_attributes::test]
+    async fn stub_transport_asyncstd1() {
+        use lettre::AsyncStd1Transport;
+
+        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();
+    }
+
+    #[cfg(feature = "tokio02")]
+    #[tokio::test]
+    async fn stub_transport_tokio02() {
+        use lettre::Tokio02Transport;
+
+        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();
+    }
 }