SHSelfHostIndex

Courier Mail Server vs Cyrus IMAP

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?
CO Courier Mail Server Integrated mail server with IMAP, POP, and webmail VS CY Cyrus IMAP Scalable IMAP and POP server for large deployments
FeatureCourier Mail ServerCyrus IMAP
CategoryMail ServersMail Servers
LicenseGPL-3.0BSD-3-Clause
LanguageCC
Setup difficultyHardHard
Min. RAM512 MB1,024 MB
Deploymentbare-metal, sourcebare-metal, source
GitHub stars★ 13★ 641
First released20001994
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 Cyrus IMAP if…

  • Released under the BSD-3-Clause license
  • Written in C
Cyrus IMAP details

Frequently asked questions

Is Courier Mail Server or Cyrus IMAP better?

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

Are Courier Mail Server and Cyrus IMAP free and open-source?

Yes. Courier Mail Server is licensed under GPL-3.0 and Cyrus IMAP under BSD-3-Clause. Both can be self-hosted at no software cost.

Can I run Courier Mail Server and Cyrus IMAP with Docker?

Courier Mail Server: check the project docs for container support. Cyrus IMAP: check the project docs for container support.

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