The Cyrus IMAP server is

electronic mail Electronic mail (usually shortened to email; alternatively hyphenated e-mail) is a method of transmitting and receiving Digital media, digital messages using electronics, electronic devices over a computer network. It was conceived in the ...

server Server may refer to: Computing *Server (computing), a computer program or a device that provides requested information for other programs or devices, called clients. Role * Waiting staff, those who work at a restaurant or a bar attending custome ...

software developed by

Carnegie Mellon University Carnegie Mellon University (CMU) is a private research university in Pittsburgh, Pennsylvania, United States. The institution was established in 1900 by Andrew Carnegie as the Carnegie Technical Schools. In 1912, it became the Carnegie Institu ...

. It differs from other

Internet Message Access Protocol In computing, the Internet Message Access Protocol (IMAP) is an Internet standard protocol used by email clients to retrieve email messages from a mail server over a TCP/IP connection. IMAP is defined by . IMAP was designed with the goal of per ...

(IMAP) server implementations in that it is generally intended to be run on sealed servers, where normal users cannot log in.

Overview

The mail spool uses a filesystem layout and format similar to the

Maildir The Maildir e-mail format is a common way of storing email messages on a file system, rather than in a database. Each message is assigned a Computer file, file with a unique name, and each mail folder is a file system directory containing these fil ...

format used by other popular

email Electronic mail (usually shortened to email; alternatively hyphenated e-mail) is a method of transmitting and receiving Digital media, digital messages using electronics, electronic devices over a computer network. It was conceived in the ...

servers such as

qmail qmail is a mail transfer agent (MTA) that runs on Unix. It was written, starting December 1995, by Daniel J. Bernstein as a more secure alternative to the popular Sendmail program. Originally license-free software, qmail's source code wa ...

Courier A courier is a person or organization that delivers a message, package or letter from one place or person to another place or person. Typically, a courier provides their courier service on a commercial contract basis; however, some couriers are ...

, Dovecot, etc. Users can access mail through the

JMAP The JSON Meta Application Protocol (JMAP) is a set of related open Internet Standard protocols for handling email. JMAP is implemented using JSON APIs over HTTP and has been developed as an alternative to IMAP and proprietary email APIs such as Go ...

IMAP In computing, the Internet Message Access Protocol (IMAP) is an Internet standard protocol used by email clients to retrieve email messages from a mail server over a TCP/IP connection. IMAP is defined by . IMAP was designed with the goal of per ...

/IMAP-S,

POP3 In computing, the Post Office Protocol (POP) is an application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a mail server. Today, POP version 3 (POP3) is the most commonly used version. Together with IMAP, i ...

/POP3-S or

KPOP K-pop (; an abbreviation of "Korean popular music") is a form of popular music originating in South Korea. It emerged in the 1990s as a form of youth subculture, with Korean musicians taking influence from Western Electronic dance music, danc ...

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

Sieve A sieve (), fine mesh strainer, or sift is a tool used for separating wanted elements from unwanted material or for controlling the particle size distribution of a sample, using a screen such as a woven mesh or net or perforated sheet m ...

. The private mailbox database design gives the server considerable advantages in

efficiency Efficiency is the often measurable ability to avoid making mistakes or wasting materials, energy, efforts, money, and time while performing a task. In a more general sense, it is the ability to do things well, successfully, and without waste. ...

scalability Scalability is the property of a system to handle a growing amount of work. One definition for software systems specifies that this may be done by adding resources to the system. In an economic context, a scalable business model implies that ...

, 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 Calendaring Extensions to WebDAV, or CalDAV, is an Internet standard allowing a client to access and manage calendar data along with the ability to schedule meetings with users on the same or on remote servers. It lets multiple users in differe ...

and

CardDAV vCard Extensions to WebDAV (CardDAV) is an address book client/server protocol designed to allow users to access and share contact data on a server. The CardDAV protocol was developed by the IETF and was published as in August 2011. CardDAV is ...

to provide an integrated calendaring and email solution, and also support for viewing email via an

RSS reader In computing, a news aggregator, also termed a feed aggregator, content aggregator, feed reader, news reader, or simply an aggregator, is client software or a web application that aggregates digital content such as online newspapers, blogs, po ...

. In terms of user management, it has a simple implementation of SASL which is specified in the Internet Standard RFC 2222.

History

Prior to 1994,

'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 The Andrew Project was a distributed computing environment developed at Carnegie Mellon University beginning in 1982. It was an ambitious project for its time and resulted in an unprecedentedly vast and accessible university computing infrastructu ...

. 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 A freshman, fresher, first year, or colloquially frosh, is a person in the first year at an educational institution, usually a secondary school or at the college and university level, but also in other forms of post-secondary school, post-se ...

(the class of 2002) on the Cyrus server for the first time and in December 2001,

board Board or Boards may refer to: Flat surface * Lumber, or other rigid material, milled or sawn flat ** Plank (wood) ** Cutting board ** Sounding board, of a musical instrument * Cardboard (paper product) * Paperboard * Fiberboard ** Hardboard, a ...

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 develope
Cyrus "Murder"
clustering, 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 AOL (formerly a company known as AOL Inc. and originally known as America Online) is an American web portal and online service provider based in New York City, and a brand marketed by Yahoo! Inc. (2017–present), Yahoo! Inc. The service tra ...

; and Rob Siemborski worked on

Gmail Gmail is the email service provided by Google. it had 1.5 billion active user (computing), users worldwide, making it the largest email service in the world. It also provides a webmail interface, accessible through a web browser, and is also ...

infrastructure at Google. 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. Cyrus is still being actively developed. Carnegie Mellon University remains active in development, and also provides the infrastructure on which cyrusimap.org runs. Staff at

Fastmail Fastmail is an Email hosting service, email hosting company based in Melbourne, Victoria, Melbourne, Australia. In addition to its Fastmail-branded services, the company also operates Topicbox, a Electronic mailing list, mailing list service, and ...

contribute much of the recent work, as they depend upon it as part of their commercial service.

References

Bibliography

* * * * * * * *

External links

* {{Email servers Message transfer agents Free email server software Email server software for Linux Carnegie Mellon University software

Overview

History

See also

References

Bibliography

External links