Docker Mailserver vs mailcow
A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.
mailcow
Dockerized full-stack mail server suite
| Feature | Docker Mailserver | mailcow |
|---|---|---|
| Deploy effort | ≈5-minute setup | Under-an-hour setup |
| Health score | 96 · Excellent | 94 · Excellent |
| Category | Mail Servers | Mail Servers |
| License | MIT | GPL-3.0 |
| Language | Shell | JavaScript |
| Setup difficulty | Medium | Medium |
| Min. RAM | 2,048 MB | 6,144 MB |
| Deployment | docker | docker |
| GitHub stars | ★ 18,872 | ★ 13,498 |
| First released | 2015 | 2016 |
| Replaces | Google Workspace, Microsoft 365 | Microsoft Exchange, Google Workspace |
What are Docker Mailserver and mailcow?
Docker Mailserver
Docker Mailserver is a single-container mail server built on Postfix and Dovecot with no external database. It is configured entirely through files and environment variables for a reproducible setup.
- Single container, no database
- Postfix and Dovecot core
- SpamAssassin and ClamAV integration
- File-based configuration
mailcow
mailcow is a complete, Docker-based mail server solution that bundles Postfix, Dovecot, Rspamd, SOGo, and a modern web UI. It makes running a full-featured mail server with antispam and webmail straightforward.
- Complete Docker mail stack
- Rspamd antispam built in
- SOGo webmail and ActiveSync
- Modern management UI with API
Docker Mailserver vs mailcow: key differences
Docker Mailserver is written in Shell, while mailcow is built with JavaScript. Licensing differs — MIT for Docker Mailserver versus GPL-3.0 for mailcow. Docker Mailserver is the lighter option, starting around 2,048 MB of RAM against 6,144 MB for mailcow.
Why pick each one
Choose Docker Mailserver if…
- Reproducible, version-controllable config
- Lightweight
Watch out for
- No built-in webmail
- Requires comfort with mail concepts
Choose mailcow if…
- All components preconfigured
- Active community
Watch out for
- Substantial RAM requirements
- Many containers to manage
Frequently asked questions
Is Docker Mailserver or mailcow better?
Neither is universally better. Docker Mailserver has the larger community; both share a medium setup difficulty, so the decision comes down to features and licensing.
Are Docker Mailserver and mailcow free and open-source?
Yes. Docker Mailserver is licensed under MIT and mailcow under GPL-3.0. Both can be self-hosted at no software cost.
Can I run Docker Mailserver and mailcow with Docker?
Docker Mailserver: yes. mailcow: yes.
Which is lighter on resources, Docker Mailserver or mailcow?
Docker Mailserver has the smaller minimum footprint at 2,048 MB of RAM, compared to about 6,144 MB for mailcow. Real-world usage depends on library size, user count, and enabled features.