Mailcow — #4 Alternative to Gmail / Outlook

Name: Mailcow
Rating: 4.82 (644 reviews)

Dockerized open-source groupware suite with SOGo webmail, Rspamd, and ActiveSync

Mailcow orchestrates Postfix, Dovecot, Rspamd, SOGo groupware, and ClamAV inside cleanly versioned Docker containers with a polished admin panel, OAuth2/OIDC SSO, and mobile Exchange ActiveSync.

License: GPL-3.0 · Pricing: Free & Open Source · Compare all Gmail / Outlook alternatives · Official Website