
Mailu
Mailu is a full-featured mail server distributed as Docker images, providing SMTP/IMAP/POP3, webmail, administration UI, and built-in security and anti-spam features.

Mailu is a simple yet full-featured email server distributed as a set of Docker images. It provides the core protocols needed to run your own mail infrastructure, plus webmail and an administration interface.
Key Features
- SMTP, Submission, IMAP/IMAP+, and optional POP3 support
- Multiple webmail options and a built-in administration UI
- Aliases, domain aliases, custom routing, auto-forward and auto-reply
- Fetched accounts (fetchmail-style) and ManageSieve support
- Per-domain delegation, global admins, announcements, and mailbox quotas
- Security features including enforced TLS, Let’s Encrypt integration, outgoing DKIM, DMARC/SPF, and anti-spoofing options
- Anti-spam features such as greylisting and auto-learning, plus optional antivirus scanning
Use Cases
- Hosting email for personal domains or small organizations with a web-based admin panel
- Running multi-domain mail hosting with delegated per-domain administration
- Deploying a containerized mail stack with DKIM/DMARC/SPF and spam filtering
Limitations and Considerations
- Deliverability depends on correct DNS configuration (SPF, DKIM, DMARC, rDNS) and IP reputation
- Operating a mail server requires ongoing maintenance (TLS, spam rules, storage quotas, and monitoring)
Mailu focuses on providing a complete, containerized mail stack using standard components rather than a full groupware suite. It is designed to be straightforward to deploy and maintain while offering the security and administrative features expected from a modern mail server.