mailcow: dockerized is an open-source groupware and email suite designed to provide a comprehensive, "all-around carefree" mail server solution using Docker containers.

The main features of this tool include:

• Modular Docker Architecture: Every part of the mail server—from the database to the webmail—runs in its own isolated container (including Postfix, Dovecot, MariaDB, and Nginx), making the stack easy to deploy and maintain.

• Powerful Web Interface (mailcow UI): A central graphical dashboard allows administrators to manage domains and mailboxes, generate DKIM/ARC keys, and handle complex tasks with just a few clicks.

• Integrated Security & Anti-Spam: It features a robust security stack including Rspamd for self-learning spam protection, ClamAV for antivirus scanning, and a built-in Netfilter system for Fail2ban-like intrusion prevention.

• Automated SSL Management: The system includes an ACME container that automatically generates and renews Let's Encrypt certificates to ensure all communication is encrypted.

• Advanced Authentication: To secure access, it supports various Two-Factor Authentication (TFA) methods, including TOTP, Yubikey OTP, and WebAuthn (FIDO2).

• Comprehensive Groupware Features: It integrates SOGo, providing a full-featured webmailer along with CalDAV and CardDAV interfaces for syncing calendars and contacts.

• Built-in Monitoring & Reliability: A dedicated Watchdog service monitors the health of all containers, while integrated logging and quarantine systems help administrators troubleshoot issues quickly.

• Flexible User Tools: Mailbox users can create temporary spam aliases, manage their own spam scores, toggle TLS enforcement, and use imapsync to migrate mail from other providers.

• Extensive Integration Support: It is designed to work with a wide range of clients (iOS, Android, Outlook, Thunderbird) and supports third-party integrations like Nextcloud, Gitea, and Matrix.