Cyrus IMAP server

Cyrus IMAP server

Developer(s)	Carnegie Mellon University
Stable release	2.4.10 / July 5, 2011; 4 months ago (2011-07-05)
Type	Mail Delivery Agent
License	original BSD license
Website	http://www.cyrusimap.org/

The Cyrus IMAP server differs from other IMAP server implementations in that it is generally intended to be run on sealed servers, where normal users cannot log in. The mail spool uses a filesystem layout and format similar to the Maildir format used by other popular email servers such as qmail, Courier, Dovecot, etc. Cyrus IMAP's spool format, said^{[by whom?]} to have improved performance and scalability to Maildir, resides in parts of the filesystem that are private to the Cyrus IMAP system. Users can access mail through the IMAP/IMAP-S, POP3/POP3-S or KPOP protocols.

The Cyrus IMAP server supports server-side mail filtering through the implementation of a mail filtering language called Sieve.

The private mailbox database design gives the server considerable advantages in efficiency, scalability, and administratability. Multiple concurrent read/write connections to the same mailbox are permitted. The server supports access control lists on mailboxes and storage quotas on mailbox hierarchies.

History

Prior to 1994, Carnegie Mellon University exclusively used the locally-developed and non-standard Andrew Messaging System (AMS) for its email communication needs. Originally written in the early 1980s as part of the Andrew Project, it was very advanced for its day. However, it had major scalability issues. Carnegie Mellon wanted to move to a standards-compliant mail system that met or exceeded the feature set of AMS, and with an emphasis on disconnected operation and scalability (scalability both in simultaneous online accesses and in large mailboxes).

The Cyrus Project was started by the Computing Services Division at Carnegie Mellon in 1994 to attempt to meet these goals. The following documents that date from that era describe the original goals of the project (they may be dated somewhat):

• Cyrus Project Goals
• Cyrus Technology Overview

Carnegie Mellon placed all of its incoming freshmen on the Cyrus server for the first time in 1998 (class of 2002). In December 2001, bboard access (which had been being mirrored from AMS to Cyrus), cut over to Cyrus completely. AMS was finally phased out in May 2002.

As development on the project progressed, it became clear that users required further scalability and additional reliability beyond that which a single-machine configuration could provide. To meet these goals, the Cyrus "Murder" clustering solution was developed again by the Computing Services Division, and after several revisions it was deployed to Carnegie Mellon in the summer of 2002.

See also

• Comparison of mail servers

References

• Rob Siemborski (2003-07-24). "Cyrus History". http://www.cyrusimap.org/mediawiki/index.php/Cyrus_History. Retrieved 2007-01-13.  - Copied with permission.

External links

• Home Page