Cyrus IMAP vs iRedMail
A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Cyrus IMAP | iRedMail |
|---|---|---|
| Deploy effort | Read-the-docs project | Read-the-docs project |
| Health score | 80 · Excellent | 82 · Excellent |
| Category | Mail Servers | Mail Servers |
| License | BSD-3-Clause | GPL-3.0 |
| Language | C | Shell |
| Setup difficulty | Hard | Medium |
| Min. RAM | 1,024 MB | 4,096 MB |
| Deployment | bare-metal, source | bare-metal |
| GitHub stars | ★ 648 | ★ 1,844 |
| First released | 1994 | 2007 |
| Replaces | Microsoft Exchange | Microsoft Exchange, Google Workspace |
What are Cyrus IMAP and iRedMail?
Cyrus IMAP
Cyrus IMAP is an enterprise-grade mail server designed to scale to very large numbers of mailboxes, with its own optimized mail store. It supports IMAP, POP, JMAP, and server-side search.
- Scales to many mailboxes
- Optimized mail store
- JMAP and IMAP support
- Server-side search
iRedMail
iRedMail is a shell-script-driven mail server deployment that sets up Postfix, Dovecot, antispam, and webmail on major Linux and BSD systems. It supports OpenLDAP, MySQL, or PostgreSQL backends.
- Automated full mail stack install
- LDAP, MySQL or PostgreSQL backends
- SpamAssassin and ClamAV
- Roundcube and SOGo webmail
Cyrus IMAP vs iRedMail: key differences
Cyrus IMAP is written in C, while iRedMail is built with Shell. Licensing differs — BSD-3-Clause for Cyrus IMAP versus GPL-3.0 for iRedMail. Cyrus IMAP is the lighter option, starting around 1,024 MB of RAM against 4,096 MB for iRedMail. Cyrus IMAP is the more established project (first released 1994), while iRedMail arrived in 2007. IRedMail has the considerably larger community, at 1,844 GitHub stars versus 648.
Why pick each one
Choose iRedMail if…
- Works on many distros
- Long-standing project
Watch out for
- Admin panel features gated in pro edition
- Script-based, less reproducible
Frequently asked questions
Is Cyrus IMAP or iRedMail better?
iRedMail is the stronger all-round pick: it has both the larger community and the simpler medium setup. Consider Cyrus IMAP if its specific feature set fits your needs better.
Are Cyrus IMAP and iRedMail free and open-source?
Yes. Cyrus IMAP is licensed under BSD-3-Clause and iRedMail under GPL-3.0. Both can be self-hosted at no software cost.
Can I run Cyrus IMAP and iRedMail with Docker?
Cyrus IMAP: check the project docs for container support. iRedMail: check the project docs for container support.
Which is lighter on resources, Cyrus IMAP or iRedMail?
Cyrus IMAP has the smaller minimum footprint at 1,024 MB of RAM, compared to about 4,096 MB for iRedMail. Real-world usage depends on library size, user count, and enabled features.