SHSelfHostIndex

Mailu 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?
MA Mailu Simple yet full-featured Docker mail server VS CI Citadel All-in-one groupware, mail and collaboration server
FeatureMailuCitadel
CategoryMail ServersGroupware
LicenseMITGPL-3.0
LanguagePythonC
Setup difficultyMediumMedium
Min. RAM2,048 MB512 MB
Deploymentdocker, kubernetesbare-metal, source
GitHub stars★ 7,443★ 100
First released20161987
ReplacesGoogle Workspace, Microsoft 365Microsoft Exchange, Microsoft 365

Why pick each one

Choose Mailu if…

  • Lighter than mailcow
  • Kubernetes support
Mailu details

Choose Citadel if…

  • Single-package setup
  • Low resource needs
Citadel details

Frequently asked questions

Is Mailu or Citadel better?

Neither is universally better. Mailu has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.

Are Mailu and Citadel free and open-source?

Yes. Mailu is licensed under MIT and Citadel under GPL-3.0. Both can be self-hosted at no software cost.

Can I run Mailu and Citadel with Docker?

Mailu: yes. Citadel: check the project docs for container support.

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