IMAP Server

Open-source Internet Message Access Protocol server designed to be secure, fast, robust and scalable.

Key features

Latest standards

IMAP4rev2 full compliance and compatible with IMAP4rev1.

Multiple Extensions

Supports ManageSieve and dozens of IMAP4 extensions.

Powered by Rust

Incredibly fast while ensuring memory safety. No runtimes or garbage collectors.

Frequently asked questions

If you have a question that is not listed here you may use the contact form below or write to us on Discord.

You can get help from the community by starting a discussion on Github or Discord. You may also become a sponsor and get support directly from Stalwart Labs Ltd.
Stalwart IMAP stores all metadata and settings in SQLite or in FoundationDB, a high performance distributed database. E-mail messages are stored separately from metadata, directly in the file system using Maildir or alternatively on the S3-storage of your choice.