# mail-send
[](https://crates.io/crates/mail-send)
[](https://github.com/stalwartlabs/mail-send/actions/workflows/rust.yml)
[](https://docs.rs/mail-send)
[](http://www.apache.org/licenses/LICENSE-2.0)
_mail-send_ is a Rust library to build, sign and send e-mail messages via SMTP. It includes the following features:
- Generates **e-mail** messages conforming to the Internet Message Format standard (_RFC 5322_).
- Full **MIME** 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 over **TLS** (_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:
```rust
// Build a simple multipart message
let 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:
```rust
// Build a simple text message with a single attachment
let 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-SHA256
let 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 the [`mail-builder`](https://crates.io/crates/mail-builder) crate.
Please note that this library does not support parsing e-mail messages as this functionality is provided separately by the [`mail-parser`](https://crates.io/crates/mail-parser) crate.
## Testing
To run the testsuite:
```bash
$ cargo test --all-features
```
or, to run the testsuite with MIRI:
```bash
$ cargo +nightly miri test --all-features
```
## License
Licensed under either of
- Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
at your option.
## Copyright
Copyright (C) 2020-2022, Stalwart Labs Ltd.