Skip to content

IMAP client library for Rust


Apache-2.0, MIT licenses found

Licenses found

Notifications You must be signed in to change notification settings


Folders and files

Last commit message
Last commit date

Latest commit


Repository files navigation

imap Documentation Crate License Codecov Dependency status

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).

This crate is looking for maintainers — reach out to @jonhoo if you're interested.

To connect, use the [ClientBuilder]. 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.

fn fetch_inbox_top() -> imap::error::Result<Option<String>> {

    let client = imap::ClientBuilder::new("", 993).connect()?;

    // 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("", "password")
        .map_err(|e| e.0)?;

    // we want to fetch the first email in the INBOX mailbox"INBOX")?;

    // 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


Opting out of native_tls

For situations where using openssl becomes problematic, you can disable the default feature which provides integration with the native_tls crate. One major reason you might want to do this is cross-compiling. To opt out of native_tls, add this to your Cargo.toml file:

version = "<some version>"
default-features = false

Even without native_tls, you can still use TLS by leveraging the pure Rust rustls crate, which is enabled with the rustls-tls feature. See the example/ file for a working example.

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:1.6.15
$ docker run -it --rm -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:1.6.15

Another alternative is to test against cyrus imapd which is a more complete IMAP implementation that greenmail (supporting quotas and ACLs).

$ docker pull outoforder/cyrus-imapd-tester
$ docker run -it --rm -p 3025:25 -p 3110:110 -p 3143:143 -p 3465:465 -p 3993:993 outoforder/cyrus-imapd-tester:latest


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.