mail-send 0.5.0

mail-send

mail-send is a Rust library to build, sign and send e-mail messages via SMTP. It includes the following features:

• Generatese-mail messages conforming to the Internet Message Format standard (RFC 5322).
• FullMIME support (RFC 2045 - 2049) with automatic selection of the most optimal encoding for each message body part.
• DomainKeys Identified Mail (DKIM) Signatures (RFC 6376) with ED25519-SHA256, RSA-SHA256 and RSA-SHA1 support.
• Simple Mail Transfer Protocol (SMTP;RFC 5321) delivery.
• SMTP Service Extension for Secure SMTP overTLS (RFC 3207).
• SMTP Service Extension for Authentication (RFC 4954) with automatic mechanism negotiation (from most secure to least secure):
  • CRAM-MD5 (RFC 2195)
  • DIGEST-MD5 (RFC 2831; obsolete but still supported)
  • XOAUTH2 (Google proprietary)
  • LOGIN
  • PLAIN
• Full async (requires Tokio).

Usage Example

Send a message via an SMTP server that requires authentication:

// Build a simple multipart messagelet message=MessageBuilder::new().from(("John Doe","john@example.com")).to(vec![("Jane Doe","jane@example.com"),("James Smith","james@test.com"),]).subject("Hi!").html_body("<h1>Hello, world!</h1>").text_body("Hello world!");// Connect to the SMTP submissions port, upgrade to TLS and// authenticate using the provided credentials.SmtpClientBuilder::new("smtp.gmail.com",587).implicit_tls(false).credentials(("john","p4ssw0rd")).connect().await.unwrap().send(message).await.unwrap();

Sign a message with DKIM and send it via an SMTP relay server:

// Build a simple text message with a single attachmentlet message=MessageBuilder::new().from(("John Doe","john@example.com")).to("jane@example.com").subject("Howdy!").text_body("These pretzels are making me thirsty.").attachment("image/png","pretzels.png",[1,2,3,4].as_ref());// Sign an e-mail message using RSA-SHA256let pk_rsa=RsaKey::<Sha256>::from_rsa_pem(TEST_KEY).unwrap();let signer=DkimSigner::from_key(pk_rsa).domain("example.com").selector("default").headers(["From","To","Subject"]).expiration(60*60*7);// Number of seconds before this signature expires (optional)// Connect to an SMTP relay server over TLS.// Signs each message with the configured DKIM signer.SmtpClientBuilder::new("smtp.gmail.com",465).connect().await.unwrap().send_signed(message,&signer).await.unwrap();

More examples of how to build messages are available in themail-builder crate.Please note that this library does not support parsing e-mail messages as this functionality is provided separately by themail-parser crate.

Testing

To run the testsuite:

$ cargo test --all-features

or, to run the testsuite with MIRI:

$ cargo +nightly miri test --all-features

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE orhttp://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT orhttp://opensource.org/licenses/MIT)

at your option.

Copyright

Copyright (C) 2020-2022, Stalwart Labs Ltd.