Alternatives to Cyrus IMAP
An open-source email, contacts and calendar server with IMAP, JMAP, CalDAV and CardDAV support. The listings below can replace it for an important use case. Each note says what changes if you switch.
The original
Cyrus IMAP
An open-source email, contacts and calendar server with IMAP, JMAP, CalDAV and CardDAV support.
Replacements
Listings that take over the same core job as Cyrus IMAP.
Dovecot
An open-source IMAP and POP3 server that stores mailboxes and serves them to mail clients.
Dovecot is a very widely deployed open-source IMAP and POP3 server with Sieve filtering, but it covers mailboxes only, without calendars or contacts.
Mox
An all-in-one open-source mail server for low-maintenance self-hosted email.
Mox bundles SMTP, IMAP and webmail in a single low-maintenance program, but lacks calendar and contact serving and is less widely deployed.
Mailu
A full-featured self-hosted mail server delivered as a set of Docker images.
Mailu delivers a full mail server as Docker images with webmail, an admin interface and antispam, replacing Cyrus with a container-based stack.
docker-mailserver
A complete mail server with SMTP, IMAP, antispam and antivirus, packaged as a single container.
docker-mailserver packages SMTP, IMAP, antispam and antivirus in one container, without webmail, calendars or a graphical admin interface.
Similar software
Related functionality, not a direct replacement.
Postfix
A widely used open-source mail transfer agent for routing and delivering email.
Exim
An open-source mail transfer agent for Unix systems with flexible routing and mail checking.
OpenSMTPD
A free SMTP server from the OpenBSD project for sending and receiving email.
Google Postmaster Tools
Google's web dashboard for checking a sending domain's reputation and mail deliverability to Gmail.
