Courier Mail Server 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?
Courier Mail Server
Integrated mail server with IMAP, POP, and webmail
VS
Exim
Flexible and widely deployed mail transfer agent
| Feature | Courier Mail Server | Exim |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | GPL-3.0 | GPL-2.0 |
| Language | C | C |
| Setup difficulty | Hard | Hard |
| Min. RAM | 512 MB | 64 MB |
| Deployment | bare-metal, source | bare-metal, source |
| GitHub stars | ★ 13 | ★ 786 |
| First released | 2000 | 1995 |
| Replaces | Microsoft Exchange | Microsoft Exchange |
Why pick each one
Choose Courier Mail Server if…
- Released under the GPL-3.0 license
- Written in C
- Lightweight — runs in 512 MB RAM
Frequently asked questions
Is Courier Mail Server or Exim better?
Neither is universally better. Exim has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are Courier Mail Server and Exim free and open-source?
Yes. Courier Mail Server is licensed under GPL-3.0 and Exim under GPL-2.0. Both can be self-hosted at no software cost.
Can I run Courier Mail Server and Exim with Docker?
Courier Mail Server: check the project docs for container support. Exim: check the project docs for container support.