Mail-in-a-Box vs Exim
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?
Mail-in-a-Box
Turn a fresh server into a working mail server
VS
Exim
Flexible and widely deployed mail transfer agent
| Feature | Mail-in-a-Box | Exim |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | CC0-1.0 | GPL-2.0 |
| Language | Python | C |
| Setup difficulty | Easy | Hard |
| Min. RAM | 1,024 MB | 64 MB |
| Deployment | bare-metal, one-click | bare-metal, source |
| GitHub stars | ★ 15,385 | ★ 786 |
| First released | 2014 | 1995 |
| Replaces | Google Workspace, Microsoft 365 | Microsoft Exchange |
Why pick each one
Frequently asked questions
Is Mail-in-a-Box or Exim better?
Mail-in-a-Box is the stronger all-round pick: it has both the larger community and the simpler easy setup. Consider Exim if its specific feature set fits your needs better.
Are Mail-in-a-Box and Exim free and open-source?
Yes. Mail-in-a-Box is licensed under CC0-1.0 and Exim under GPL-2.0. Both can be self-hosted at no software cost.
Can I run Mail-in-a-Box and Exim with Docker?
Mail-in-a-Box: check the project docs for container support. Exim: check the project docs for container support.