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mailcow: dockerized - ๐Ÿฎ + ๐Ÿณ = ๐Ÿ’•

The mailserver suite with the 'moo'

What is mailcow: dockerized?

Question

Mailcow, MailCow or mailcow? What is the exact name of the project?

Correct: mailcow, because mailcow is a registered word mark with a small m ๐Ÿ˜

mailcow: dockerized is an open source groupware/email suite based on docker.

mailcow relies on many well known and long used components, which in combination result in an all around carefree email server.

Each container represents a single application, connected in a bridged network:

  • ACME Automatic generation of Let's Encrypt certificates
  • ClamAV Antivirus scanner (optional)
  • Dovecot IMAP/POP server for retrieving e-mails with integrated Full-Text Search Engine "Flatcurve"
  • MariaDB Database for storing user information etc.
  • Memcached Cache for the webmailer SOGo
  • Netfilter Fail2ban-like integration of @mkuron
  • Nginx Web server for components of the stack
  • Olefy Analysis of Office documents for viruses, macros, etc.
  • PHP Programming language of most web-based mailcow applications
  • Postfix MTA (Mail Transfer Agent) for e-mail traffic on the Internet
  • Redis Storage for spam information, DKIM key, etc.
  • Rspamd Spam filter with automatic learning of spam mails
  • SOGo Integrated webmailer and Cal-/Carddav interface
  • Solr Full text search for IMAP connections to quickly search emails (Deprecated) (Optional)
  • Unbound Integrated DNS server for verifying DNSSEC etc.
  • Watchdog For basic monitoring of the container status within mailcow

But the heart of mailcow is the graphical web interface, the mailcow UI.

It offers a place for almost all settings and allows the comfortable creation of new domains and email addresses with just a few clicks.

But also other or more tricky tasks can be done in it with ease:

  • DKIM and ARC support/generation.
  • Black and white lists per domain and per user.
  • Spam score management per user (reject spam, flag spam, greylist).
  • Allow mailbox users to create temporary spam aliases
  • Prepend email tags to subject or move emails to subfolders (per user)
  • Allow mailbox users to toggle TLS enforcement for inbound and outbound messages
  • Users can reset caches on SOGo ActiveSync devices
  • imapsync to periodically migrate or retrieve remote mailboxes
  • TFA: Yubikey OTP and WebAuthn USB (Google Chrome and derivatives only), TOTP
  • Add whitelist hosts to forward mail to mailcow
  • Fail2ban-like integration
  • Quarantine system
  • Anti-virus scanning including macro scanning in Office documents
  • Integrated basic monitoring
  • And much more...

The mailcow data (such as emails, user data, etc.) is stored in Docker volumes - take good care of these volumes:

  • clamd-db-vol-1
  • crypt-vol-1
  • mysql-socket-vol-1
  • mysql-vol-1
  • postfix-vol-1
  • redis-vol-1
  • rspamd-vol-1
  • sogo-userdata-backup-vol-1
  • sogo-web-vol-1
  • solr-vol-1
  • vmail-index-vol-1
  • vmail-vol-1

Warning

The mails are compressed and encrypted. The key pair can be found in crypt-vol-1. Please don't forget to backup this and other volumes. #nobackupnopity


Support the mailcow project

Please consider a support contract for a small monthly fee at Servercow1 to support further development. We support you while you support us. :)

If you are super awesome and would like to support without a contract, you can get a SAL (Stay-Awesome License) that confirms your awesomeness (a flexible one-time payment) at Servercow.


Need help?

There are two ways to achieve support for your mailcow installation.

Commercial support

For professional and prioritized commercial support you can sign a basic support subscription at Servercow. For custom inquiries or questions please contact us at info@servercow.de instead.

Furthermore we do also provide a fully featured and managed mailcow here. This way we take care about the technical magic underneath and you can enjoy your whole mail experience in a hassle-free way.

Community support and chat

The other alternative is our free community-support on our various channels below. Please notice, that this support is driven by our awesome community around mailcow. This kind of support is best-effort, voluntary and there is no guarantee for anything.

Telegram desktop clients are available for multiple platforms. You can search the groups history for keywords.

For bug tracking, feature requests and code contributions only:

News and release informations

For announcements and release informations you can find us on:

Or alternatively on our blog:


Interested? Try it out right away!

Have we got your interest? Get a first overview of the functionalities of mailcow and your mailcow UI in our official mailcow demos!

Since September 2022 weยดre providing two seperate Demo instances:

  • demo.mailcow.email is the classic Demo based on the stable releases.
  • nightly-demo.mailcow.email is the new nightly demo based on unreleased testing features. (So especially interesting for those who have no possibility to create a test instance themselves.)

Use these credentials for the demos

  • Administrator: admin / moohoo
  • Domain-Administrator: department / moohoo
  • Mailbox: demo@440044.xyz / moohoo

The login credentials work for both variants.

Always up to date

The demo instances get the latest updates directly after releases from GitHub. Fully automatic, without any downtime!


  1. Servercow is a hosting/support division of The Infrastructure Company GmbH (mailcow maintainer).