Stalwart IMAP Server #

Stalwart IMAP is an open-source Internet Message Access Protocol server designed to be secure, fast, robust and scalable. A JSON Meta Application Protocol (JMAP) backend such as Stalwart JMAP is required to use Stalwart IMAP (in other words, Stalwart IMAP is an imap4-to-jmap proxy).

Key features:

• IMAP4 and ManageSieve server:
  • IMAP4rev2 (RFC 9051) full compliance.
  • IMAP4rev1 (RFC 3501) backwards compatible.
  • ManageSieve (RFC 5804) server with support for all extensions.
• Support for multiple IMAP extensions:
  • Access Control Lists (ACL) (RFC 4314)
  • Conditional Store and Quick Resynchronization (RFC 7162)
  • SORT and THREAD (RFC 5256)
  • Message Preview Generation (RFC 8970)
  • And many other extensions…
• JMAP proxy features:
  • Proxies IMAP4 and ManageSieve requests to JMAP requests.
  • High-availability and fault-tolerance support when using a Stalwart JMAP backend.
  • Full support for JMAP Core, JMAP Mail and JMAP for Sieve Scripts.
• Secure:
  • OAuth 2.0 authorization code and device authorization flows.
  • Rate limiting.
  • Memory safe (thanks to Rust).

Get Started #

Install Stalwart IMAP on your server by following the instructions for your platform:

• Linux / MacOS
• Windows
• Docker

You may also compile Stalwart IMAP from the source.

Support #

If you are having problems running Stalwart IMAP, you found a bug or just have a question, do not hesitate to reach us on Github Discussions or Discord. Additionally you may become a sponsor to obtain priority support from Stalwart Labs Ltd.

Documentation #

Table of Contents

• Get Started
  • Linux / MacOS
  • Windows
  • Docker
• Configuration
  • Overview
  • IMAP Server
  • JMAP Proxy
  • ManageSieve
  • Cache
• Development
  • Compiling
  • Tests
  • RFCs conformed