What is Cyrus IMAP?¶
Cyrus IMAP is an email, contacts and calendar server. Cyrus is free and open source.
This is the documentation for version 3.4.5 of Cyrus IMAP: stable branch.
The latest development version 3.7.0-alpha0 is at https://www.cyrusimap.org/dev/.
CardDAV and CalDAV support
Robust data storage
Scalable for large installations
Flexible filtering support through Sieve
Supports antivirus and antispam toolkits
Handles deliverability: SPF, DKIM, DMARC
Extensive authentication options, through Cyrus SASL
Long list of supported standards
Read more in our full list of features.
Cyrus has been under active development since the year 1993 when the project was launched at Carnegie Mellon University. It’s used in production systems around the world, at universities and in private enterprise.
Need help? We have active mailing lists.
- Get Cyrus
- Release Notes
- Notes for Packagers
- Quickstart Guide
- Installing Cyrus
- Upgrading to 3.4
- 1. Preparation
- 2. Install new 3.4 Cyrus
- 3. Shut down existing Cyrus
- 4. Backup and Copy existing data
- 5. Copy config files and update
- 6. Upgrade specific items
- 7. Start new 3.4 Cyrus and verify
- 8. Reconstruct databases and cache
- 9. Do you want any new features?
- 10. Upgrade complete
- Special note for Murder configurations
- Configuration Guide
- We need your help
- Contribute docs
- Contribute code and tests
- Cyrus Internals
- Unit Tests
What is Cyrus SASL?¶
Simple Authentication and Security Layer (SASL) is a specification that describes how authentication mechanisms can be plugged into an application protocol on the wire. Cyrus SASL is an implementation of SASL that makes it easy for application developers to integrate authentication mechanisms into their application in a generic way.
The latest stable version of Cyrus SASL is 2.1.28.