Cyrus IMAP

cyrusimap.org · checked 3 Oct 2026

#17 · Email Server Software #19 · Mail Server Software

Visit cyrusimap.org ↗ Alternatives Cyrus IMAP vs Zimbra Collaboration

How it plugs in

—Public API

NoOpen source

YesFree tier

Signal on Email Server Software5.9#17 of 33

Cyrus IMAP is an email, contacts, and calendar server.

Pricing

Cyrus IMAPFree and open source server softwareFree

As cyrusimap.org lists them, checked 3 Oct 2026.

Near it

All alternatives →

Runs on

Web
Windows
Mac
Linux
iOS
Android

Facts

Website: cyrusimap.org
Price: Free tier
Free trial: No
Antivirus and antispam: The project says Cyrus supports antivirus and antispam toolkits.
Authentication: Cyrus uses Cyrus SASL and supports multiple authentication options.
Download: Cyrus is available as source tarballs or source from Git, and as packages for major distributions; distribution packages may not be up to date.
Filtering: It supports server-side email filtering through Sieve.
Founded: 1993
Integrations: The installation guide describes receiving mail from SMTP servers such as Sendmail, Postfix, and Exim through LMTP.
Intended users: The project says Cyrus is used in production at universities and private enterprises.
Mail delivery: It supports email deliverability features including SPF, DKIM, and DMARC.
Open source: The project describes Cyrus as free and open source.
Protocols: Cyrus supports JMAP, IMAP, POP3, CalDAV, and CardDAV.
Scale and reliability: The project lists replication, robust data storage, and scalability for large installations among its features.
Security: The feature documentation lists Kerberos, LDAP, and SQL authentication, access control, and a sealed system design.

On these boards

Built Cyrus IMAP?

Claim the page, then edit your card yourself from your member desk: its name, words, logo, screenshots, plans and links. Your desk shows how many readers open it.

Claim Cyrus IMAP