Prepare 0.11.4 (#936)

.github/workflows/test.yml

@@ -75,8 +75,8 @@ jobs:
             rust: stable
           - name: beta
             rust: beta
-          - name: 1.65.0
+          - name: '1.70'
-            rust: 1.65.0
+            rust: '1.70'
 
     steps:
       - name: Checkout

CHANGELOG.md

@@ -1,5 +1,60 @@
+<a name="v0.11.4"></a>
+### v0.11.4 (2024-01-28)
+
+#### Bug fixes
+
+* Percent decode credentials in SMTP connect URL ([#932], [#934])
+* Fix mimebody DKIM body-hash computation ([#923])
+
+[#923]: https://github.com/lettre/lettre/pull/923
+[#932]: https://github.com/lettre/lettre/pull/932
+[#934]: https://github.com/lettre/lettre/pull/934
+
+<a name="v0.11.3"></a>
+### v0.11.3 (2024-01-02)
+
+#### Features
+
+* Derive `Clone` for `FileTransport` and `AsyncFileTransport` ([#924])
+* Derive `Debug` for `SmtpTransport` ([#925])
+
+#### Misc
+
+* Upgrade `rustls` to v0.22 ([#921])
+* Drop once_cell dependency in favor of OnceLock from std ([#928])
+
+[#921]: https://github.com/lettre/lettre/pull/921
+[#924]: https://github.com/lettre/lettre/pull/924
+[#925]: https://github.com/lettre/lettre/pull/925
+[#928]: https://github.com/lettre/lettre/pull/928
+
+<a name="v0.11.2"></a>
+### v0.11.2 (2023-11-23)
+
+#### Upgrade notes
+
+* MSRV is now 1.70 ([#916])
+
+#### Misc
+
+* Bump `idna` to v0.5 ([#918])
+* Bump `boring` and `tokio-boring` to v4 ([#915])
+
+[#915]: https://github.com/lettre/lettre/pull/915
+[#916]: https://github.com/lettre/lettre/pull/916
+[#918]: https://github.com/lettre/lettre/pull/918
+
+<a name="v0.11.1"></a>
+### v0.11.1 (2023-10-24)
+
+#### Bug fixes
+
+* Fix `webpki-roots` certificate store setup ([#909])
+
+[#909]: https://github.com/lettre/lettre/pull/909
+
 <a name="v0.11.0"></a>
-### v0.11.0 (2023-08-15)
+### v0.11.0 (2023-10-15)
 
 While this release technically contains breaking changes, we expect most projects
 to be able to upgrade by only bumping the version in `Cargo.toml`.

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "lettre"
 # remember to update html_root_url and README.md (Cargo.toml example and deps.rs badge)
-version = "0.11.0"
+version = "0.11.4"
 description = "Email client"
 readme = "README.md"
 homepage = "https://lettre.rs"
@@ -11,7 +11,7 @@ authors = ["Alexis Mousset <contact@amousset.me>", "Paolo Barbolini <paolo@paolo
 categories = ["email", "network-programming"]
 keywords = ["email", "smtp", "mailer", "message", "sendmail"]
 edition = "2021"
-rust-version = "1.65"
+rust-version = "1.70"
 
 [badges]
 is-it-maintained-issue-resolution = { repository = "lettre/lettre" }
@@ -20,8 +20,7 @@ maintenance = { status = "actively-developed" }
 
 [dependencies]
 chumsky = "0.9"
-idna = "0.4"
+idna = "0.5"
-once_cell = { version = "1", optional = true }
 tracing = { version = "0.1.16", default-features = false, features = ["std"], optional = true } # feature
 
 # builder
@@ -42,14 +41,15 @@ nom = { version = "7", optional = true }
 hostname = { version = "0.3", optional = true } # feature
 socket2 = { version = "0.5.1", optional = true }
 url = { version = "2.4", optional = true }
+percent-encoding = { version = "2.3", optional = true }
 
 ## tls
 native-tls = { version = "0.2.5", optional = true } # feature
-rustls = { version = "0.21", features = ["dangerous_configuration"], optional = true }
+rustls = { version = "0.22.1", optional = true }
-rustls-pemfile = { version = "1", optional = true }
+rustls-pemfile = { version = "2", optional = true }
-rustls-native-certs = { version = "0.6.2", optional = true }
+rustls-native-certs = { version = "0.7", optional = true }
-webpki-roots = { version = "0.25", optional = true }
+webpki-roots = { version = "0.26", optional = true }
-boring = { version = "3", optional = true }
+boring = { version = "4", optional = true }
 
 # async
 futures-io = { version = "0.3.7", optional = true }
@@ -59,13 +59,13 @@ async-trait = { version = "0.1", optional = true }
 ## async-std
 async-std = { version = "1.8", optional = true }
 #async-native-tls = { version = "0.3.3", optional = true }
-futures-rustls = { version = "0.24", optional = true }
+futures-rustls = { version = "0.25", optional = true }
 
 ## tokio
 tokio1_crate = { package = "tokio", version = "1", optional = true }
 tokio1_native_tls_crate = { package = "tokio-native-tls", version = "0.3", optional = true }
-tokio1_rustls = { package = "tokio-rustls", version = "0.24", optional = true }
+tokio1_rustls = { package = "tokio-rustls", version = "0.25", optional = true }
-tokio1_boring = { package = "tokio-boring", version = "3", optional = true }
+tokio1_boring = { package = "tokio-boring", version = "4", optional = true }
 
 ## dkim
 sha2 = { version = "0.10", optional = true, features = ["oid"] }
@@ -85,7 +85,7 @@ walkdir = "2"
 tokio1_crate = { package = "tokio", version = "1", features = ["macros", "rt-multi-thread"] }
 async-std = { version = "1.8", features = ["attributes"] }
 serde_json = "1"
-maud = "0.25"
+maud = "0.26"
 
 [[bench]]
 harness = false
@@ -104,7 +104,7 @@ mime03 = ["dep:mime"]
 file-transport = ["dep:uuid", "tokio1_crate?/fs", "tokio1_crate?/io-util"]
 file-transport-envelope = ["serde", "dep:serde_json", "file-transport"]
 sendmail-transport = ["tokio1_crate?/process", "tokio1_crate?/io-util", "async-std?/unstable"]
-smtp-transport = ["dep:base64", "dep:nom", "dep:socket2", "dep:once_cell", "dep:url", "tokio1_crate?/rt", "tokio1_crate?/time", "tokio1_crate?/net"]
+smtp-transport = ["dep:base64", "dep:nom", "dep:socket2", "dep:url", "dep:percent-encoding", "tokio1_crate?/rt", "tokio1_crate?/time", "tokio1_crate?/net"]
 
 pool = ["dep:futures-util"]
 

README.md

@@ -28,8 +28,8 @@
 </div>
 
 <div align="center">
-  <a href="https://deps.rs/crate/lettre/0.11.0">
+  <a href="https://deps.rs/crate/lettre/0.11.4">
-    <img src="https://deps.rs/crate/lettre/0.11.0/status.svg"
+    <img src="https://deps.rs/crate/lettre/0.11.4/status.svg"
       alt="dependency status" />
   </a>
 </div>
@@ -53,12 +53,12 @@ Lettre does not provide (for now):
 ## Supported Rust Versions
 
 Lettre supports all Rust versions released in the last 6 months. At the time of writing
-the minimum supported Rust version is 1.65, but this could change at any time either from
+the minimum supported Rust version is 1.70, but this could change at any time either from
 one of our dependencies bumping their MSRV or by a new patch release of lettre.
 
 ## Example
 
-This library requires Rust 1.65 or newer.
+This library requires Rust 1.70 or newer.
 To use this library, add the following to your `Cargo.toml`:
 
 ```toml

src/lib.rs

@@ -6,7 +6,7 @@
 //! * Secure defaults
 //! * Async support
 //!
-//! Lettre requires Rust 1.65 or newer.
+//! Lettre requires Rust 1.70 or newer.
 //!
 //! ## Features
 //!
@@ -109,7 +109,7 @@
 //! [mime 0.3]: https://docs.rs/mime/0.3
 //! [DKIM]: https://datatracker.ietf.org/doc/html/rfc6376
 
-#![doc(html_root_url = "https://docs.rs/crate/lettre/0.11.0")]
+#![doc(html_root_url = "https://docs.rs/crate/lettre/0.11.4")]
 #![doc(html_favicon_url = "https://lettre.rs/favicon.ico")]
 #![doc(html_logo_url = "https://avatars0.githubusercontent.com/u/15113230?v=4")]
 #![forbid(unsafe_code)]

src/message/mimebody.rs

@@ -17,6 +17,16 @@ pub(super) enum Part {
     Multi(MultiPart),
 }
 
+impl Part {
+    #[cfg(feature = "dkim")]
+    pub(super) fn format_body(&self, out: &mut Vec<u8>) {
+        match self {
+            Part::Single(part) => part.format_body(out),
+            Part::Multi(part) => part.format_body(out),
+        }
+    }
+}
+
 impl EmailFormat for Part {
     fn format(&self, out: &mut Vec<u8>) {
         match self {
@@ -132,6 +142,12 @@ impl SinglePart {
         self.format(&mut out);
         out
     }
+
+    /// Format only the signlepart body
+    fn format_body(&self, out: &mut Vec<u8>) {
+        out.extend_from_slice(&self.body);
+        out.extend_from_slice(b"\r\n");
+    }
 }
 
 impl EmailFormat for SinglePart {
@@ -139,8 +155,7 @@ impl EmailFormat for SinglePart {
         write!(out, "{}", self.headers)
             .expect("A Write implementation panicked while formatting headers");
         out.extend_from_slice(b"\r\n");
-        out.extend_from_slice(&self.body);
+        self.format_body(out);
-        out.extend_from_slice(b"\r\n");
     }
 }
 
@@ -373,14 +388,9 @@ impl MultiPart {
         self.format(&mut out);
         out
     }
-}
-
-impl EmailFormat for MultiPart {
-    fn format(&self, out: &mut Vec<u8>) {
-        write!(out, "{}", self.headers)
-            .expect("A Write implementation panicked while formatting headers");
-        out.extend_from_slice(b"\r\n");
 
+    /// Format only the multipart body
+    fn format_body(&self, out: &mut Vec<u8>) {
         let boundary = self.boundary();
 
         for part in &self.parts {
@@ -396,6 +406,15 @@ impl EmailFormat for MultiPart {
     }
 }
 
+impl EmailFormat for MultiPart {
+    fn format(&self, out: &mut Vec<u8>) {
+        write!(out, "{}", self.headers)
+            .expect("A Write implementation panicked while formatting headers");
+        out.extend_from_slice(b"\r\n");
+        self.format_body(out);
+    }
+}
+
 #[cfg(test)]
 mod test {
     use pretty_assertions::assert_eq;

src/message/mod.rs

@@ -525,7 +525,7 @@ impl Message {
     pub(crate) fn body_raw(&self) -> Vec<u8> {
         let mut out = Vec::new();
         match &self.body {
-            MessageBody::Mime(p) => p.format(&mut out),
+            MessageBody::Mime(p) => p.format_body(&mut out),
             MessageBody::Raw(r) => out.extend_from_slice(r),
         };
         out.extend_from_slice(b"\r\n");

src/transport/file/mod.rs

@@ -157,7 +157,7 @@ mod error;
 type Id = String;
 
 /// Writes the content and the envelope information to a file
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[cfg_attr(docsrs, doc(cfg(feature = "file-transport")))]
 pub struct FileTransport {
@@ -167,7 +167,7 @@ pub struct FileTransport {
 }
 
 /// Asynchronously writes the content and the envelope information to a file
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[cfg_attr(docsrs, doc(cfg(any(feature = "tokio1", feature = "async-std1"))))]
 #[cfg(any(feature = "async-std1", feature = "tokio1"))]

src/transport/smtp/client/async_net.rs

@@ -16,6 +16,8 @@ use futures_io::{
 };
 #[cfg(feature = "async-std1-rustls-tls")]
 use futures_rustls::client::TlsStream as AsyncStd1RustlsTlsStream;
+#[cfg(any(feature = "tokio1-rustls-tls", feature = "async-std1-rustls-tls"))]
+use rustls::pki_types::ServerName;
 #[cfg(feature = "tokio1-boring-tls")]
 use tokio1_boring::SslStream as Tokio1SslStream;
 #[cfg(feature = "tokio1")]
@@ -350,7 +352,6 @@ impl AsyncNetworkStream {
 
                 #[cfg(feature = "tokio1-rustls-tls")]
                 return {
-                    use rustls::ServerName;
                     use tokio1_rustls::TlsConnector;
 
                     let domain = ServerName::try_from(domain.as_str())
@@ -358,7 +359,7 @@ impl AsyncNetworkStream {
 
                     let connector = TlsConnector::from(config);
                     let stream = connector
-                        .connect(domain, tcp_stream)
+                        .connect(domain.to_owned(), tcp_stream)
                         .await
                         .map_err(error::connection)?;
                     Ok(InnerAsyncNetworkStream::Tokio1RustlsTls(stream))
@@ -424,14 +425,13 @@ impl AsyncNetworkStream {
                 #[cfg(feature = "async-std1-rustls-tls")]
                 return {
                     use futures_rustls::TlsConnector;
-                    use rustls::ServerName;
 
                     let domain = ServerName::try_from(domain.as_str())
                         .map_err(|_| error::connection("domain isn't a valid DNS name"))?;
 
                     let connector = TlsConnector::from(config);
                     let stream = connector
-                        .connect(domain, tcp_stream)
+                        .connect(domain.to_owned(), tcp_stream)
                         .await
                         .map_err(error::connection)?;
                     Ok(InnerAsyncNetworkStream::AsyncStd1RustlsTls(stream))
@@ -486,8 +486,7 @@ impl AsyncNetworkStream {
                 .unwrap()
                 .first()
                 .unwrap()
-                .clone()
+                .to_vec()),
-                .0),
             #[cfg(feature = "tokio1-boring-tls")]
             InnerAsyncNetworkStream::Tokio1BoringTls(stream) => Ok(stream
                 .ssl()
@@ -509,8 +508,7 @@ impl AsyncNetworkStream {
                 .unwrap()
                 .first()
                 .unwrap()
-                .clone()
+                .to_vec()),
-                .0),
             InnerAsyncNetworkStream::None => panic!("InnerNetworkStream::None must never be built"),
         }
     }

src/transport/smtp/client/net.rs

@@ -12,7 +12,7 @@ use boring::ssl::SslStream;
 #[cfg(feature = "native-tls")]
 use native_tls::TlsStream;
 #[cfg(feature = "rustls-tls")]
-use rustls::{ClientConnection, ServerName, StreamOwned};
+use rustls::{pki_types::ServerName, ClientConnection, StreamOwned};
 use socket2::{Domain, Protocol, Type};
 
 #[cfg(any(feature = "native-tls", feature = "rustls-tls", feature = "boring-tls"))]
@@ -189,7 +189,7 @@ impl NetworkStream {
             InnerTlsParameters::RustlsTls(connector) => {
                 let domain = ServerName::try_from(tls_parameters.domain())
                     .map_err(|_| error::connection("domain isn't a valid DNS name"))?;
-                let connection = ClientConnection::new(Arc::clone(connector), domain)
+                let connection = ClientConnection::new(Arc::clone(connector), domain.to_owned())
                     .map_err(error::connection)?;
                 let stream = StreamOwned::new(connection, tcp_stream);
                 InnerNetworkStream::RustlsTls(stream)
@@ -241,8 +241,7 @@ impl NetworkStream {
                 .unwrap()
                 .first()
                 .unwrap()
-                .clone()
+                .to_vec()),
-                .0),
             #[cfg(feature = "boring-tls")]
             InnerNetworkStream::BoringTls(stream) => Ok(stream
                 .ssl()

src/transport/smtp/client/tls.rs

@@ -1,6 +1,6 @@
 use std::fmt::{self, Debug};
 #[cfg(feature = "rustls-tls")]
-use std::{sync::Arc, time::SystemTime};
+use std::{io, sync::Arc};
 
 #[cfg(feature = "boring-tls")]
 use boring::{
@@ -11,8 +11,10 @@ use boring::{
 use native_tls::{Protocol, TlsConnector};
 #[cfg(feature = "rustls-tls")]
 use rustls::{
-    client::{ServerCertVerified, ServerCertVerifier, WebPkiVerifier},
+    client::danger::{HandshakeSignatureValid, ServerCertVerified, ServerCertVerifier},
-    ClientConfig, Error as TlsError, RootCertStore, ServerName,
+    crypto::{verify_tls12_signature, verify_tls13_signature},
+    pki_types::{CertificateDer, ServerName, UnixTime},
+    ClientConfig, DigitallySignedStruct, Error as TlsError, RootCertStore, SignatureScheme,
 };
 
 #[cfg(any(feature = "native-tls", feature = "rustls-tls", feature = "boring-tls"))]
@@ -115,7 +117,7 @@ pub enum CertificateStore {
     /// Use a hardcoded set of Mozilla roots via the `webpki-roots` crate.
     ///
     /// This option is only available in the rustls backend.
-    #[cfg(feature = "webpki-roots")]
+    #[cfg(feature = "rustls-tls")]
     WebpkiRoots,
     /// Don't use any system certificates.
     None,
@@ -337,8 +339,6 @@ impl TlsParametersBuilder {
     #[cfg(feature = "rustls-tls")]
     #[cfg_attr(docsrs, doc(cfg(feature = "rustls-tls")))]
     pub fn build_rustls(self) -> Result<TlsParameters, Error> {
-        let tls = ClientConfig::builder();
-
         let just_version3 = &[&rustls::version::TLS13];
         let supported_versions = match self.min_tls_version {
             TlsVersion::Tlsv10 => {
@@ -351,58 +351,38 @@ impl TlsParametersBuilder {
             TlsVersion::Tlsv13 => just_version3,
         };
 
-        let tls = tls
+        let tls = ClientConfig::builder_with_protocol_versions(supported_versions);
-            .with_safe_default_cipher_suites()
-            .with_safe_default_kx_groups()
-            .with_protocol_versions(supported_versions)
-            .map_err(error::tls)?;
 
         let tls = if self.accept_invalid_certs {
-            tls.with_custom_certificate_verifier(Arc::new(InvalidCertsVerifier {}))
+            tls.dangerous()
+                .with_custom_certificate_verifier(Arc::new(InvalidCertsVerifier {}))
         } else {
             let mut root_cert_store = RootCertStore::empty();
 
             #[cfg(feature = "rustls-native-certs")]
             fn load_native_roots(store: &mut RootCertStore) -> Result<(), Error> {
                 let native_certs = rustls_native_certs::load_native_certs().map_err(error::tls)?;
-                let mut valid_count = 0;
+                let (added, ignored) = store.add_parsable_certificates(native_certs);
-                let mut invalid_count = 0;
-                for cert in native_certs {
-                    match store.add(&rustls::Certificate(cert.0)) {
-                        Ok(_) => valid_count += 1,
-                        Err(err) => {
-                            #[cfg(feature = "tracing")]
-                            tracing::debug!("certificate parsing failed: {:?}", err);
-                            invalid_count += 1;
-                        }
-                    }
-                }
                 #[cfg(feature = "tracing")]
                 tracing::debug!(
-                    "loaded platform certs with {valid_count} valid and {invalid_count} invalid certs"
+                    "loaded platform certs with {added} valid and {ignored} ignored (invalid) certs"
                 );
                 Ok(())
             }
 
-            #[cfg(feature = "webpki-roots")]
+            #[cfg(feature = "rustls-tls")]
             fn load_webpki_roots(store: &mut RootCertStore) {
-                store.add_server_trust_anchors(webpki_roots::TLS_SERVER_ROOTS.0.iter().map(|ta| {
+                store.extend(webpki_roots::TLS_SERVER_ROOTS.iter().cloned());
-                    rustls::OwnedTrustAnchor::from_subject_spki_name_constraints(
-                        ta.subject,
-                        ta.spki,
-                        ta.name_constraints,
-                    )
-                }));
             }
 
             match self.cert_store {
                 CertificateStore::Default => {
                     #[cfg(feature = "rustls-native-certs")]
                     load_native_roots(&mut root_cert_store)?;
-                    #[cfg(all(not(feature = "rustls-native-certs"), feature = "webpki-roots"))]
+                    #[cfg(not(feature = "rustls-native-certs"))]
                     load_webpki_roots(&mut root_cert_store);
                 }
-                #[cfg(feature = "webpki-roots")]
+                #[cfg(feature = "rustls-tls")]
                 CertificateStore::WebpkiRoots => {
                     load_webpki_roots(&mut root_cert_store);
                 }
@@ -410,14 +390,11 @@ impl TlsParametersBuilder {
             }
             for cert in self.root_certs {
                 for rustls_cert in cert.rustls {
-                    root_cert_store.add(&rustls_cert).map_err(error::tls)?;
+                    root_cert_store.add(rustls_cert).map_err(error::tls)?;
                 }
             }
 
-            tls.with_custom_certificate_verifier(Arc::new(WebPkiVerifier::new(
+            tls.with_root_certificates(root_cert_store)
-                root_cert_store,
-                None,
-            )))
         };
         let tls = tls.with_no_client_auth();
 
@@ -491,7 +468,7 @@ pub struct Certificate {
     #[cfg(feature = "native-tls")]
     native_tls: native_tls::Certificate,
     #[cfg(feature = "rustls-tls")]
-    rustls: Vec<rustls::Certificate>,
+    rustls: Vec<CertificateDer<'static>>,
     #[cfg(feature = "boring-tls")]
     boring_tls: boring::x509::X509,
 }
@@ -510,7 +487,7 @@ impl Certificate {
             #[cfg(feature = "native-tls")]
             native_tls: native_tls_cert,
             #[cfg(feature = "rustls-tls")]
-            rustls: vec![rustls::Certificate(der)],
+            rustls: vec![der.into()],
             #[cfg(feature = "boring-tls")]
             boring_tls: boring_tls_cert,
         })
@@ -530,10 +507,8 @@ impl Certificate {
 
             let mut pem = Cursor::new(pem);
             rustls_pemfile::certs(&mut pem)
+                .collect::<io::Result<Vec<_>>>()
                 .map_err(|_| error::tls("invalid certificates"))?
-                .into_iter()
-                .map(rustls::Certificate)
-                .collect::<Vec<_>>()
         };
 
         Ok(Self {
@@ -554,19 +529,53 @@ impl Debug for Certificate {
 }
 
 #[cfg(feature = "rustls-tls")]
+#[derive(Debug)]
 struct InvalidCertsVerifier;
 
 #[cfg(feature = "rustls-tls")]
 impl ServerCertVerifier for InvalidCertsVerifier {
     fn verify_server_cert(
         &self,
-        _end_entity: &rustls::Certificate,
+        _end_entity: &CertificateDer<'_>,
-        _intermediates: &[rustls::Certificate],
+        _intermediates: &[CertificateDer<'_>],
-        _server_name: &ServerName,
+        _server_name: &ServerName<'_>,
-        _scts: &mut dyn Iterator<Item = &[u8]>,
         _ocsp_response: &[u8],
-        _now: SystemTime,
+        _now: UnixTime,
     ) -> Result<ServerCertVerified, TlsError> {
         Ok(ServerCertVerified::assertion())
     }
+
+    fn verify_tls12_signature(
+        &self,
+        message: &[u8],
+        cert: &CertificateDer<'_>,
+        dss: &DigitallySignedStruct,
+    ) -> Result<HandshakeSignatureValid, TlsError> {
+        verify_tls12_signature(
+            message,
+            cert,
+            dss,
+            &rustls::crypto::ring::default_provider().signature_verification_algorithms,
+        )
+    }
+
+    fn verify_tls13_signature(
+        &self,
+        message: &[u8],
+        cert: &CertificateDer<'_>,
+        dss: &DigitallySignedStruct,
+    ) -> Result<HandshakeSignatureValid, TlsError> {
+        verify_tls13_signature(
+            message,
+            cert,
+            dss,
+            &rustls::crypto::ring::default_provider().signature_verification_algorithms,
+        )
+    }
+
+    fn supported_verify_schemes(&self) -> Vec<SignatureScheme> {
+        rustls::crypto::ring::default_provider()
+            .signature_verification_algorithms
+            .supported_schemes()
+    }
 }

src/transport/smtp/connection_url.rs

@@ -112,7 +112,16 @@ pub(crate) fn from_connection_url<B: TransportBuilder>(connection_url: &str) ->
     }
 
     if let Some(password) = connection_url.password() {
-        let credentials = Credentials::new(connection_url.username().into(), password.into());
+        let percent_decode = |s: &str| {
+            percent_encoding::percent_decode_str(s)
+                .decode_utf8()
+                .map(|cow| cow.into_owned())
+                .map_err(error::connection)
+        };
+        let credentials = Credentials::new(
+            percent_decode(connection_url.username())?,
+            percent_decode(password)?,
+        );
         builder = builder.credentials(credentials);
     }
 

src/transport/smtp/pool/async_impl.rs

@@ -2,7 +2,7 @@ use std::{
     fmt::{self, Debug},
     mem,
     ops::{Deref, DerefMut},
-    sync::Arc,
+    sync::{Arc, OnceLock},
     time::{Duration, Instant},
 };
 
@@ -10,7 +10,6 @@ use futures_util::{
     lock::Mutex,
     stream::{self, StreamExt},
 };
-use once_cell::sync::OnceCell;
 
 use super::{
     super::{client::AsyncSmtpConnection, Error},
@@ -22,7 +21,7 @@ pub struct Pool<E: Executor> {
     config: PoolConfig,
     connections: Mutex<Vec<ParkedConnection>>,
     client: AsyncSmtpClient<E>,
-    handle: OnceCell<E::Handle>,
+    handle: OnceLock<E::Handle>,
 }
 
 struct ParkedConnection {
@@ -41,7 +40,7 @@ impl<E: Executor> Pool<E> {
             config,
             connections: Mutex::new(Vec::new()),
             client,
-            handle: OnceCell::new(),
+            handle: OnceLock::new(),
         });
 
         {

src/transport/smtp/transport.rs

@@ -1,6 +1,6 @@
 #[cfg(feature = "pool")]
 use std::sync::Arc;
-use std::time::Duration;
+use std::{fmt::Debug, time::Duration};
 
 #[cfg(feature = "pool")]
 use super::pool::sync_impl::Pool;
@@ -38,6 +38,14 @@ impl Transport for SmtpTransport {
     }
 }
 
+impl Debug for SmtpTransport {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let mut builder = f.debug_struct("SmtpTransport");
+        builder.field("inner", &self.inner);
+        builder.finish()
+    }
+}
+
 impl SmtpTransport {
     /// Simple and secure transport, using TLS connections to communicate with the SMTP server
     ///
@@ -373,6 +381,22 @@ mod tests {
         assert!(matches!(builder.info.tls, Tls::Wrapper(_)));
         assert_eq!(builder.info.server, "smtp.example.com");
 
+        let builder = SmtpTransport::from_url(
+            "smtps://user%40example.com:pa$$word%3F%22!@smtp.example.com:465",
+        )
+        .unwrap();
+
+        assert_eq!(builder.info.port, 465);
+        assert_eq!(
+            builder.info.credentials,
+            Some(Credentials::new(
+                "user@example.com".to_owned(),
+                "pa$$word?\"!".to_owned()
+            ))
+        );
+        assert!(matches!(builder.info.tls, Tls::Wrapper(_)));
+        assert_eq!(builder.info.server, "smtp.example.com");
+
         let builder =
             SmtpTransport::from_url("smtp://username:password@smtp.example.com:587?tls=required")
                 .unwrap();