msmtp vs OpenSMTPD

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?
FeaturemsmtpOpenSMTPD
CategoryMail ServersMail Servers
LicenseGPL-3.0ISC
LanguageCC
Setup difficultyEasyMedium
Min. RAM32 MB32 MB
Deploymentbinary, sourcebare-metal, source
GitHub stars★ 290★ 579
First released20042013
ReplacesSendmailSendmail, Postfix

Why pick each one

Choose msmtp if…

  • Released under the GPL-3.0 license
  • Easy to set up — beginner-friendly
  • Written in C
  • Tiny footprint — runs in 32 MB RAM
msmtp details

Choose OpenSMTPD if…

  • Clean concise config
  • Strong security record
OpenSMTPD details

Frequently asked questions

Is msmtp or OpenSMTPD better?

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

Are msmtp and OpenSMTPD free and open-source?

Yes. msmtp is licensed under GPL-3.0 and OpenSMTPD under ISC. Both can be self-hosted at no software cost.

Can I run msmtp and OpenSMTPD with Docker?

msmtp: check the project docs for container support. OpenSMTPD: check the project docs for container support.

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