DKIMpy Milter vs Postal

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?
FeatureDKIMpy MilterPostal
CategoryMail ServersMail Servers
LicenseGPL-2.0MIT
LanguagePythonRuby
Setup difficultyMediumHard
Min. RAM64 MB2,048 MB
Deploymentbare-metal, sourcedocker, bare-metal
GitHub stars★ 20★ 16,724
First released20182017
ReplacesHosted email authenticationSendGrid, Mailgun, Postmark

Why pick each one

Choose DKIMpy Milter if…

  • Released under the GPL-2.0 license
  • Written in Python
  • Tiny footprint — runs in 64 MB RAM
DKIMpy Milter details

Choose Postal if…

  • Great for application email
  • Strong API
Postal details

Frequently asked questions

Is DKIMpy Milter or Postal better?

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

Are DKIMpy Milter and Postal free and open-source?

Yes. DKIMpy Milter is licensed under GPL-2.0 and Postal under MIT. Both can be self-hosted at no software cost.

Can I run DKIMpy Milter and Postal with Docker?

DKIMpy Milter: check the project docs for container support. Postal: yes.

Related comparisons