OpenSMTPD
Secure SMTP server implementation from the OpenBSD project.
- Email Servers
- C
- ISC
- Actively maintained
GitHub stats
- GitHub stars
- 586
- Forks
- 105
- Open issues
- 114
- Commits, last 12 months
- 61
- Last commit
- Sep 14, 2026
- Latest release
- 7.9.0p0Sep 13, 2026
- Created
- Jun 19, 2012
Data from the GitHub API, refreshed daily.
About OpenSMTPD
Secure SMTP server implementation from the OpenBSD project. OpenSMTPD is open source under the ISC license and written mainly in C, so you can read the code, run it on your own hardware and keep full control of your data.
The project has 586 stars and 105 forks on GitHub, with 61 commits over the last year. It installs natively rather than through an official Docker image, so plan for a short manual setup.
Repository preview
Similar apps
More apps like OpenSMTPD
Other projects in Email Servers, ranked by GitHub stars.
docker-mailserver
docker-mailserver/docker-mailserver
Production-ready fullstack but simple mail server (SMTP, IMAP, LDAP, Antispam, Antivirus, etc.) running inside a container. Only configuration files, no SQL database.
Email ServersShellDockerPostal
postalserver/postal
Complete and fully featured mail server for use by websites & web servers.
Email ServersRubyDockerMail-in-a-Box
mail-in-a-box/mailinabox
Turns any Ubuntu server into a fully functional mail server with one command.
Email ServersPythonStalwart Mail Server
stalwartlabs/stalwart
All-in-one mail server with JMAP, IMAP4, and SMTP support and a wide range of modern features.
Email ServersRustDockerMailcow
mailcow/mailcow-dockerized
Mail server suite based on Dovecot, Postfix and other open source software, that provides a modern Web UI for administration.
Email ServersJavaScriptDockerMailu
Mailu/Mailu
Simple yet full-featured mail server as a set of Docker images.
Email ServersPythonDocker
What is OpenSMTPD?
OpenSMTPD is a free, open-source app you can host on your own server, listed in our Email Servers category. Secure SMTP server implementation from the OpenBSD project. The source code lives at github.com/OpenSMTPD/OpenSMTPD, where it has 586 stars.
Is OpenSMTPD free and open source?
Yes. OpenSMTPD is open-source software released under the ISC license, so you can self-host it at no cost. You only pay for the server it runs on, and some projects also offer an optional paid cloud plan.
Can I run OpenSMTPD with Docker?
OpenSMTPD does not list an official Docker image. It installs natively (C and deb), so follow the install steps in its README or look for a community-maintained container.
What are the best alternatives to OpenSMTPD?
Popular open-source alternatives to OpenSMTPD include docker-mailserver, Postal and Mail-in-a-Box.
Is OpenSMTPD actively maintained?
The most recent commit to OpenSMTPD was on Sep 14, 2026 with 61 commits in the past twelve months. The latest release is 7.9.0p0, published Sep 13, 2026. Check the open issues on GitHub to gauge how quickly maintainers respond.