Cyrus IMAP server
The Cyrus IMAP server is electronic mail server software developed by Carnegie Mellon University. It differs from other Internet Message Access Protocol (IMAP) server implementations in that it is generally intended to be run on sealed servers, where normal users cannot log in.
Developer(s) | Carnegie Mellon University, Fastmail |
---|---|
Stable release | 3.2.3[1]
/ August 28, 2020 |
Repository | |
Written in | C |
Type | Mail delivery agent |
License | BSD |
Website | www |
Overview
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. 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.
As of version 2.4.17, there is support for CalDAV and CardDAV to provide an integrated calendaring and email solution, and also support for viewing email via an RSS reader.
History
Prior to 1994, Carnegie Mellon University's email was based on the locally-developed and non-standard Andrew Messaging System (AMS) - written in the early 1980s as part of the Andrew Project. This was very advanced for its day, but had major scalability issues and Carnegie Mellon wanted to move to a standards-compliant mail system that met or exceeded the feature set of AMS.
In 1994 the Computing Services Division at Carnegie Mellon addressed these goals by starting the Cyrus Project. In 1998, Carnegie Mellon placed all of its incoming freshmen (the class of 2002) on the Cyrus server for the first time and in December 2001, bboard access (which had been mirrored from AMS to Cyrus), was cut over to Cyrus completely. AMS was finally phased out in May 2002.
The Computing Services Division later developed Cyrus "Murder" clustering,[lower-alpha 1] and after several revisions deployed it within Carnegie Mellon in the summer of 2002.
Several members of the Cyrus development team at Carnegie Mellon went on to become leaders in the development of large-scale electronic mail infrastructure elsewhere: John Gardiner Myers was Chief Architect of Host Mail Infrastructure at America Online;[3] and Rob Siemborski worked on Gmail infrastructure at Google.[4]
In the fall of 2016 Carnegie Mellon announced the retirement of Cyrus IMAP as their electronic mail storage service, with Cyrus users required to choose between on-campus Microsoft Exchange and Google "G Suite" off-campus mail.[5]
Cyrus is still being actively developed. Carnegie Mellon University remains active in development, and also provides the infrastructure on which cyrusimap.org runs.[6] Staff at Fastmail contribute much of the recent work, as they depend upon it as part of their commercial service.[7][6][8]
References
- "Releases - cyrusimap/cyrus-imapd". Retrieved 6 August 2019 – via GitHub.
- "Cyrus Murder - Concepts". Appendix C. Retrieved 28 May 2017.
- "John Gardiner Myers". Retrieved 17 February 2018.
- "RFC 4954". Retrieved 17 February 2018.
- "Cyrus Retirement". Retrieved 17 February 2018.
- "Who Is Cyrus". Retrieved 22 December 2018.
- "Why we contribute to Cyrus IMAP". Retrieved 22 December 2018.
- "Cyrus development and release plans". Retrieved 17 February 2018.
- The term "murder" is borrowed from the commonly-used collective noun for crows.[2]
Bibliography
- Bauer, Mick (2003). "Paranoid penguin: secure mail with LDAP and IMAP, Part I". Linux Journal. 2003 (115, November 2003): 12 – via ACM.CS1 maint: ref=harv (link)
- Bautts, Tony; Dawson, Terry; Purdy, Gregor N. (2005). Linux network administrator's guide. O'Reilly Media. ISBN 9780596005481.CS1 maint: ref=harv (link)
- Christenson, Nick (2003). Sendmail Performance Tuning. Addison-Wesley Professional. ISBN 9780321115706.CS1 maint: ref=harv (link)
- Glennon, Katharine, ed. (2000). E-Mail Virus Protection Handbook: Protect Your E-mail from Trojan Horses, Viruses, and Mobile Code Attacks. Elsevier. ISBN 9780080477534.CS1 maint: ref=harv (link)
- Golubitsky, Chaos (2005). Toward an Automated Vulnerability Comparison of Open Source IMAP Servers (PDF). 19th Large Installation System Administration Conference (LISA ’05). USENIX.CS1 maint: ref=harv (link)
- Mullet, Dianna; Mullet, Kevin (2000). Managing IMAP. O'Reilly Media. ISBN 9780596000127.CS1 maint: ref=harv (link)
- Smith, Roderick W. (2003). Linux Power Tools. Wiley. ISBN 9780782142266.CS1 maint: ref=harv (link)
- Smith, Roderick W. (2011). LPIC-2 Linux Professional Institute Certification Study Guide: Exams 201 and 202. John Wiley & Sons. ISBN 9781118100448.CS1 maint: ref=harv (link)