Docker Mailserver vs RainLoop

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?
FeatureDocker MailserverRainLoop
CategoryMail ServersMail Servers
LicenseMITAGPL-3.0
LanguageShellPHP
Setup difficultyMediumEasy
Min. RAM2,048 MB128 MB
Deploymentdockerdocker, bare-metal, source
GitHub stars★ 18,682★ 4,120
First released20152013
ReplacesGoogle Workspace, Microsoft 365Gmail, Outlook Web

Why pick each one

Choose Docker Mailserver if…

  • Reproducible, version-controllable config
  • Lightweight
Docker Mailserver details

Choose RainLoop if…

  • Released under the AGPL-3.0 license
  • Easy to set up — beginner-friendly
  • First-class Docker support for quick deployment
  • Active community (4.1k GitHub stars)
RainLoop details

Frequently asked questions

Is Docker Mailserver or RainLoop better?

Neither is universally better. Docker Mailserver has the larger community, while RainLoop is simpler to set up (easy difficulty). Choose based on the comparison table above and your own setup.

Are Docker Mailserver and RainLoop free and open-source?

Yes. Docker Mailserver is licensed under MIT and RainLoop under AGPL-3.0. Both can be self-hosted at no software cost.

Can I run Docker Mailserver and RainLoop with Docker?

Docker Mailserver: yes. RainLoop: yes.

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