Postal vs Lieer

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?
FeaturePostalLieer
CategoryMail ServersMail Servers
LicenseMITGPL-3.0
LanguageRubyPython
Setup difficultyHardMedium
Min. RAM2,048 MB128 MB
Deploymentdocker, bare-metalbinary, source
GitHub stars★ 16,724★ 649
First released20172017
ReplacesSendGrid, Mailgun, PostmarkGmail web interface

Why pick each one

Choose Postal if…

  • Great for application email
  • Strong API
Postal details

Choose Lieer if…

  • Released under the GPL-3.0 license
  • Written in Python
  • Tiny footprint — runs in 128 MB RAM
Lieer details

Frequently asked questions

Is Postal or Lieer better?

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

Are Postal and Lieer free and open-source?

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

Can I run Postal and Lieer with Docker?

Postal: yes. Lieer: check the project docs for container support.

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