mailcow 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?
mailcow
Dockerized full-stack mail server suite
VS
OpenSMTPD
Secure and simple SMTP server from OpenBSD
| Feature | mailcow | OpenSMTPD |
|---|---|---|
| Category | Mail Servers | Mail Servers |
| License | GPL-3.0 | ISC |
| Language | JavaScript | C |
| Setup difficulty | Medium | Medium |
| Min. RAM | 6,144 MB | 32 MB |
| Deployment | docker | bare-metal, source |
| GitHub stars | ★ 13,245 | ★ 579 |
| First released | 2016 | 2013 |
| Replaces | Microsoft Exchange, Google Workspace | Sendmail, Postfix |
Why pick each one
Frequently asked questions
Is mailcow or OpenSMTPD better?
Neither is universally better. mailcow has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are mailcow and OpenSMTPD free and open-source?
Yes. mailcow is licensed under GPL-3.0 and OpenSMTPD under ISC. Both can be self-hosted at no software cost.
Can I run mailcow and OpenSMTPD with Docker?
mailcow: yes. OpenSMTPD: check the project docs for container support.