Chatmail Relay vs MongooseIM

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?
FeatureChatmail RelayMongooseIM
CategoryChat & CommunicationMatrix & XMPP
LicenseMPL-2.0GPL-2.0
LanguagePythonErlang
Setup difficultyMediumHard
Min. RAM512 MB1,024 MB
Deploymentdocker, bare-metaldocker, bare-metal, source
GitHub stars★ 476★ 1,748
First released20232012
ReplacesWhatsApp, SignalSlack, WhatsApp

Why pick each one

Choose Chatmail Relay if…

  • Uses open email standards
  • Hard to censor
Chatmail Relay details

Choose MongooseIM if…

  • Released under the GPL-2.0 license
  • First-class Docker support for quick deployment
  • Active community (1.7k GitHub stars)
  • Written in Erlang
MongooseIM details

Frequently asked questions

Is Chatmail Relay or MongooseIM better?

Neither is universally better. MongooseIM has the larger community, while Chatmail Relay is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.

Are Chatmail Relay and MongooseIM free and open-source?

Yes. Chatmail Relay is licensed under MPL-2.0 and MongooseIM under GPL-2.0. Both can be self-hosted at no software cost.

Can I run Chatmail Relay and MongooseIM with Docker?

Chatmail Relay: yes. MongooseIM: yes.

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