Postal vs Apache SpamAssassin

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?
FeaturePostalApache SpamAssassin
CategoryMail ServersMail Servers
LicenseMITApache-2.0
LanguageRubyPerl
Setup difficultyHardMedium
Min. RAM2,048 MB256 MB
Deploymentdocker, bare-metalbare-metal, source
GitHub stars★ 16,724★ 341
First released20172001
ReplacesSendGrid, Mailgun, PostmarkProprietary spam filtering appliances

Why pick each one

Choose Postal if…

  • Great for application email
  • Strong API
Postal details

Choose Apache SpamAssassin if…

  • Released under the Apache-2.0 license
  • Written in Perl
  • Tiny footprint — runs in 256 MB RAM
Apache SpamAssassin details

Frequently asked questions

Is Postal or Apache SpamAssassin better?

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

Are Postal and Apache SpamAssassin free and open-source?

Yes. Postal is licensed under MIT and Apache SpamAssassin under Apache-2.0. Both can be self-hosted at no software cost.

Can I run Postal and Apache SpamAssassin with Docker?

Postal: yes. Apache SpamAssassin: check the project docs for container support.

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