IMAP client for Rust

1 stable release

2.2.0 Jul 30, 2020

#203 in Email

25 downloads per month
Used in async-imap-lite




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This crate lets you connect to and interact with servers that implement the IMAP protocol (RFC 3501 and various extensions). After authenticating with the server, IMAP lets you list, fetch, and search for e-mails, as well as monitor mailboxes for changes. It supports at least the latest three stable Rust releases (possibly even older ones; check the CI results).

To connect, use the connect function. This gives you an unauthenticated Client. You can then use Client::login or Client::authenticate to perform username/password or challenge/response authentication respectively. This in turn gives you an authenticated Session, which lets you access the mailboxes at the server.

The documentation within this crate borrows heavily from the various RFCs, but should not be considered a complete reference. If anything is unclear, follow the links to the RFCs embedded in the documentation for the various types and methods and read the raw text there!

Below is a basic client example. See the examples/ directory for more.

extern crate imap;
extern crate native_tls;

fn fetch_inbox_top() -> imap::error::Result<Option<String>> {
    let domain = "imap.example.com";
    let tls = native_tls::TlsConnector::builder().build().unwrap();

    // we pass in the domain twice to check that the server's TLS
    // certificate is valid for the domain we're connecting to.
    let client = imap::connect((domain, 993), domain, &tls).unwrap();

    // the client we have here is unauthenticated.
    // to do anything useful with the e-mails, we need to log in
    let mut imap_session = client
        .login("me@example.com", "password")
        .map_err(|e| e.0)?;

    // we want to fetch the first email in the INBOX mailbox

    // fetch message number 1 in this mailbox, along with its RFC822 field.
    // RFC 822 dictates the format of the body of e-mails
    let messages = imap_session.fetch("1", "RFC822")?;
    let message = if let Some(m) = messages.iter().next() {
    } else {
        return Ok(None);

    // extract the message's body
    let body = message.body().expect("message did not have a body!");
    let body = std::str::from_utf8(body)
        .expect("message was not valid utf-8")

    // be nice to the server and log out


Running the test suite

To run the integration tests, you need to have GreenMail running. The easiest way to do that is with Docker:

$ docker pull greenmail/standalone:1.5.9
$ docker run -t -i -e GREENMAIL_OPTS='-Dgreenmail.setup.test.all -Dgreenmail.hostname= -Dgreenmail.auth.disabled -Dgreenmail.verbose' -p 3025:3025 -p 3110:3110 -p 3143:3143 -p 3465:3465 -p 3993:3993 -p 3995:3995 greenmail/standalone:1.5.9


Licensed under either of


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.


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