Apache James vs Citadel
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?
Apache James
Enterprise mail server and SMTP/IMAP platform
VS
Citadel
All-in-one groupware, mail and collaboration server
| Feature | Apache James | Citadel |
|---|---|---|
| Category | Mail Servers | Groupware |
| License | Apache-2.0 | GPL-3.0 |
| Language | Java | C |
| Setup difficulty | Hard | Medium |
| Min. RAM | 2,048 MB | 512 MB |
| Deployment | docker, source | bare-metal, source |
| GitHub stars | ★ 1,037 | ★ 100 |
| First released | 2003 | 1987 |
| Replaces | Microsoft Exchange | Microsoft Exchange, Microsoft 365 |
Why pick each one
Choose Apache James if…
- Released under the Apache-2.0 license
- First-class Docker support for quick deployment
- Active community (1k GitHub stars)
- Written in Java
Frequently asked questions
Is Apache James or Citadel better?
Neither is universally better. Apache James has the larger community, while Citadel is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.
Are Apache James and Citadel free and open-source?
Yes. Apache James is licensed under Apache-2.0 and Citadel under GPL-3.0. Both can be self-hosted at no software cost.
Can I run Apache James and Citadel with Docker?
Apache James: yes. Citadel: check the project docs for container support.