Docker Mailserver vs Mail-in-a-Box
Docker Mailserver and Mail-in-a-Box are both email server software. Docker Mailserver is open source under MIT, with 20k GitHub stars. Mail-in-a-Box is open source under CC0-1.0, with 15k GitHub stars.
Which to pick
- Pick Docker Mailserver when
- You want a simple self-hosted mail server without a web admin panel.
- Pick Mail-in-a-Box when
- You want your own email on a dedicated VPS with as few decisions as possible.
Side by side
A single container mail server with SMTP, IMAP, anti-spam, antivirus and LDAP support, configured by files and environment variables.
A setup script that turns a fresh Ubuntu server into a complete mail server with Postfix, Dovecot, Roundcube webmail, Nextcloud contacts and calendars, spam filtering, DNS and TLS.
No GUI or webmail, and self-hosted mail brings deliverability and security work.
It takes over the whole machine, allows almost no customisation, and depends on a specific Ubuntu LTS release.
Production-ready (both)
Self-hosted server (both)
Docker, Postfix, Dovecot and Rspamd
Python, Shell, Postfix, Dovecot, Roundcube and Nextcloud
Open source, MIT (permissive)
Open source, CC0-1.0 (public domain)
You can build it into a product you sell, as long as you keep its copyright notice.
You can take the code into anything, including a product you sell, with no conditions.
20k GitHub stars
15k GitHub stars
Established: started 11 years ago, latest release v16.0.1.
Established: started 13 years ago, latest release v77.
Other comparisons
More email servers and webmail
Both sides were judged on 2026-11-03 from each project's README and GitHub data. License, age and popularity lines are worked out directly.