Lettre is a mailer library for Rust.

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Crate Docs Required Rust version MIT licensed

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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


This library requires Rust 1.32 or newer. To use this library, add the following to your Cargo.toml:

lettre = "0.9"
lettre_email = "0.9"
extern crate lettre;
extern crate lettre_email;

use lettre::{EmailTransport, SmtpTransport};
use lettre_email::EmailBuilder;
use std::path::Path;

fn main() {
    let email = EmailBuilder::new()
        // Addresses can be specified by the tuple (email, alias)
        .to(("", "Firstname Lastname"))
        // ... or by an address only
        .subject("Hi, Hello world")
        .text("Hello world.")

    // Open a local connection on port 25
    let mut mailer = SmtpTransport::builder_unencrypted_localhost().unwrap()
    // Send the email
    let result = mailer.send(&email);

    if result.is_ok() {
        println!("Email sent");
    } else {
        println!("Could not send email: {:?}", result);



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.


This program is distributed under the terms of the MIT license.

See LICENSE for details.