iRedMail 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?
iRedMail
Free, full-featured mail server solution
VS
Citadel
All-in-one groupware, mail and collaboration server
| Feature | iRedMail | Citadel |
|---|---|---|
| Category | Mail Servers | Groupware |
| License | GPL-3.0 | GPL-3.0 |
| Language | Shell | C |
| Setup difficulty | Medium | Medium |
| Min. RAM | 4,096 MB | 512 MB |
| Deployment | bare-metal | bare-metal, source |
| GitHub stars | ★ 1,835 | ★ 100 |
| First released | 2007 | 1987 |
| Replaces | Microsoft Exchange, Google Workspace | Microsoft Exchange, Microsoft 365 |
Why pick each one
Frequently asked questions
Is iRedMail or Citadel better?
Neither is universally better. iRedMail has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are iRedMail and Citadel free and open-source?
Yes. iRedMail is licensed under GPL-3.0 and Citadel under GPL-3.0. Both can be self-hosted at no software cost.
Can I run iRedMail and Citadel with Docker?
iRedMail: check the project docs for container support. Citadel: check the project docs for container support.