Fastmail vs Mailcow-dockerized
Fastmail and Mailcow-dockerized are both email server software. Fastmail is a commercial product from Fastmail Pty Ltd. Mailcow-dockerized is open source under GPL-3.0, with 14k GitHub stars.
Which to pick
- Pick Fastmail when
- An individual, family or small business wants fast, private email on its own domain without Google or Microsoft.
- Pick Mailcow-dockerized when
- You want to host email for several domains yourself with a full admin interface.
Side by side
Paid, ad-free email hosting with calendars, contacts, custom domains and masked email addresses, built on open standards (IMAP, JMAP, CalDAV).
A Docker Compose mail server suite with Postfix, Dovecot, Rspamd, SOGo webmail and groupware, and an admin UI for domains and mailboxes.
No office suite or file storage included, and data is held in Australia and the US.
Running your own mail means handling deliverability, IP reputation and security updates yourself.
Production-ready (both)
Cloud service and mobile app
Self-hosted server
Not published
Docker, Postfix, Dovecot, Rspamd, PHP and MariaDB
Closed source, sold by Fastmail Pty Ltd
Open source, GPL-3.0 (strong copyleft)
Closed source: you use it under the maker's terms and cannot change or resell the code.
Use inside your business is unrestricted, but anything you distribute that includes it must be released under the same license.
586 Wikipedia readers a month on phones
14k GitHub stars
Not known
Established: started 10 years ago, latest release 2026-10.
Other comparisons
More email servers and webmail
Both sides were judged on 2026-11-03 from makers' descriptions, Wikipedia, READMEs and GitHub data. License, age and popularity lines are worked out directly.