Courier Mail Server vs Postfix

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?
FeatureCourier Mail ServerPostfix
CategoryMail ServersMail Servers
LicenseGPL-3.0IPL-1.0
LanguageCC
Setup difficultyHardHard
Min. RAM512 MB128 MB
Deploymentbare-metal, sourcedocker, bare-metal, source
GitHub stars★ 13★ 563
First released20001998
ReplacesMicrosoft ExchangeMicrosoft Exchange

Why pick each one

Choose Courier Mail Server if…

  • Released under the GPL-3.0 license
  • Written in C
  • Lightweight — runs in 512 MB RAM
Courier Mail Server details

Choose Postfix if…

  • Battle-tested and stable
  • Extensive documentation
Postfix details

Frequently asked questions

Is Courier Mail Server or Postfix better?

Neither is universally better. Postfix has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.

Are Courier Mail Server and Postfix free and open-source?

Yes. Courier Mail Server is licensed under GPL-3.0 and Postfix under IPL-1.0. Both can be self-hosted at no software cost.

Can I run Courier Mail Server and Postfix with Docker?

Courier Mail Server: check the project docs for container support. Postfix: yes.

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