Cyrus IMAP vs Mail-in-a-Box
A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.
Not the right match-up?
Cyrus IMAP
Scalable IMAP and POP server for large deployments
VS
Mail-in-a-Box
Turn a fresh server into a working mail server
| Feature | Cyrus IMAP | Mail-in-a-Box |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | BSD-3-Clause | CC0-1.0 |
| Language | C | Python |
| Setup difficulty | Hard | Easy |
| Min. RAM | 1,024 MB | 1,024 MB |
| Deployment | bare-metal, source | bare-metal, one-click |
| GitHub stars | ★ 641 | ★ 15,385 |
| First released | 1994 | 2014 |
| Replaces | Microsoft Exchange | Google Workspace, Microsoft 365 |
Why pick each one
Frequently asked questions
Is Cyrus IMAP or Mail-in-a-Box better?
Mail-in-a-Box is the stronger all-round pick: it has both the larger community and the simpler easy setup. Consider Cyrus IMAP if its specific feature set fits your needs better.
Are Cyrus IMAP and Mail-in-a-Box free and open-source?
Yes. Cyrus IMAP is licensed under BSD-3-Clause and Mail-in-a-Box under CC0-1.0. Both can be self-hosted at no software cost.
Can I run Cyrus IMAP and Mail-in-a-Box with Docker?
Cyrus IMAP: check the project docs for container support. Mail-in-a-Box: check the project docs for container support.