Exim vs Kolab Groupware
A side-by-side comparison of two self-hosted apps from related categories — licensing, setup difficulty, resource needs, and what each one replaces.
Not the right match-up?
Exim
Flexible and widely deployed mail transfer agent
VS
Kolab Groupware
Open-source groupware server with mail and calendaring
| Feature | Exim | Kolab Groupware |
|---|---|---|
| Category | Mail Servers | Groupware |
| License | GPL-2.0 | AGPL-3.0 |
| Language | C | PHP |
| Setup difficulty | Hard | Hard |
| Min. RAM | 64 MB | 2,048 MB |
| Deployment | bare-metal, source | bare-metal, docker |
| GitHub stars | ★ 786 | ★ 200 |
| First released | 1995 | 2002 |
| Replaces | Microsoft Exchange | Microsoft Exchange, Zimbra |
Why pick each one
Choose Kolab Groupware if…
- Built on proven components
- Strong standards support
Frequently asked questions
Is Exim or Kolab Groupware 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 Exim and Kolab Groupware free and open-source?
Yes. Exim is licensed under GPL-2.0 and Kolab Groupware under AGPL-3.0. Both can be self-hosted at no software cost.
Can I run Exim and Kolab Groupware with Docker?
Exim: check the project docs for container support. Kolab Groupware: yes.