Where to Find Mailu Documentation and Release Notes

Mailu's documentation lives inside the project repository and evolves together with the code, so the version you read matters: you should open the documentation that matches the Mailu version you are actually running. Release notes for each version are listed alongside it, and a demonstration server is available if you want to see the interface and features before or after installing.

Documentation Structure

The docs are organized into a few main sections, which map to the tasks you will actually perform:

• General — concepts, philosophy, history, features and screenshots, admin interface screenshots, FAQ, and release notes.
• Setup — setting up a new Mailu server, Docker Compose requirements, Docker Compose setup, Kubernetes setup, configuration reference, setting up your DNS, using an external reverse proxy, and changing the database back-end.
• Administration — maintaining a Mailu server, the web administration interface, spam filtering, the Mailu command line, and the Mailu RESTful API.
• Contributors — contribution workflow, project guidelines, development environment, altering the database, before requesting a pull, I18N and L10N, and firewalling Mailu.

Because the documentation is written as part of the repository, it changes with each release. A page that describes a configuration option or a setup step may not apply to an older or newer Mailu version than the one it was written for.

Matching Docs to Your Version

The key rule stated in the documentation itself: make sure you access the proper version of the documentation, based on the version of Mailu you are running. In practice this means:

1. Check which Mailu version your deployment uses (for example, from your Docker Compose configuration or the release you installed).
2. Open the documentation set for that same version rather than the latest one.
3. When a step does not match what you see, treat the version mismatch as the first thing to verify.

This matters most for Setup and Administration pages, where commands, environment variables, and interface behavior can differ between releases.

Release Notes and Version History

Release notes give you the version timeline and what changed in each release. The documented releases include:

Use the release notes when you need to know whether a feature, fix, or behavior change exists in your version — for example, before following a setup guide written for a different release.

Demonstration Server

A demonstration server is documented for exploring functionality and connecting to the server, including adding domains. It is useful when you want to see the admin interface and mail features in action without committing to a full deployment, or when you are deciding whether Mailu fits your needs.

What Mailu Is, in One Paragraph

Mailu is a mail server delivered as a set of Docker images, described as free software in both senses (free of cost and open source), open to suggestions and external contributions. Its stated aim is an easily set up, easily maintained, full-featured mail server that ships no proprietary software and no unrelated features common in groupware. Documented features include a standard email server (IMAP/IMAP+, SMTP and Submission with client auto-configuration profiles), aliases, domain aliases, custom routing, full-text search of attachments, multiple webmails and an administration interface, user features such as auto-reply, auto-forward, fetched accounts and managesieve, admin features such as global admins, announcements, per-domain delegation and quotas, security features including enforced TLS, DANE, MTA-STS, Letsencrypt, outgoing DKIM, anti-virus scanning, Snuffleupagus and malicious attachment blocking, and antispam with auto-learn, greylisting, DMARC and SPF, and anti-spoofing.

Practical Checklist

• Confirm your running Mailu version before reading any setup or admin page.
• Read the documentation version that matches it, not the newest one.
• Consult release notes to place a feature or change in the correct version.
• Use the demonstration server to preview functionality and the connection flow.
• Expect the docs to move with the repository, so re-check after upgrading.