You are currently browsing documentation for the 1.5 branch. Documentation for the stable 1.6 branch can be found here.

Docker Compose setup

Prepare the environment

Mailu will store all of its persistent data in a path of your choice (/mailu by default) simply create the directory and move there:

mkdir /mailu
cd /mailu

Download the initial configuration file

Docker Compose configuration is stored in a file named docker-compose.yml. Additionally, Mailu relies on a .env file for various settings. Download the proper template files from the git repository. To download the configuration for the 1.5 branch, use:


Then open the .env file to setup the mail server. Modify the ROOT setting to match your setup directory if different from /mailu.

Modify the VERSION configuration in the .env file to reflect the version you picked.

Set the common configuration values

Open the .env file and set configuration settings after reading the configuration documentation. Some settings are specific to the Docker Compose setup.

Modify BIND_ADDRESS4 to match the public IP address assigned to your server. This address should be configured on one of the network interfaces of the server. If the address is not configured directly (NAT) on any of the network interfaces or if you would simply like the server to listen on all interfaces, use

Modify BIND_ADDRESS6 to match the public IPv6 address assigned to your server. The behavior is identical to BIND_ADDRESS4.

Set the TLS_FLAVOR to one of the following values:

  • cert is the default and requires certificates to be setup manually;
  • letsencrypt will use the Letsencrypt! CA to generate automatic ceriticates;
  • mail is similar to cert except that TLS will only be served for emails (IMAP and SMTP), not HTTP (use it behind reverse proxies);
  • notls will disable TLS, this is not recommended except for testing.

Enable optional features

Some of Mailu features are not used by every user and are thus not enabled in a default configuration.

A Webmail is a Web interface exposing an email client. Mailu webmails are bound to the internal IMAP and SMTP server for users to access their mailbox through the Web. By exposing a complex application such as a Webmail, you should be aware of the security implications caused by such an increase of attack surface. The WEBMAIL configuration option must be one of the following:

  • none is the default value, no Webmail service will be exposed;
  • roundcube will run the popular Roundcube Webmail;
  • rainloop will run the popular Rainloop Webmail.

The administration interface is not exposed on the public address by default, you will need to set the ADMIN variable accordingly:

  • true will expose the admin interface in /admin;
  • false (or any other value) will disable this behaviour.

A Webdav server exposes a Dav interface over HTTP so that clients can store contacts or calendars using the mail account. This can be enabled using the WEBDAV setting. The configuration option must be one of the following:

  • none is the default value, no webdav service will be exposed;
  • radicale exposes the radicale Webdav service.

An antivirus server helps fighting large scale virus spreading campaigns that leverage e-mail for initial infection. This can be setup using the ANTIVIRUS setting. The configuration option must be one of the following:

  • none disables antivirus checks;
  • clamav is the default values, the popular ClamAV antivirus is enabled.

Make sure that you have at least 1GB of memory for ClamAV to load its signature database.

Finish setting up TLS

Mailu relies heavily on TLS and must have a key pair and a certificate available, at least for the hostname configured in the .env file.

If you set TLS_FLAVOR to cert or if then you must create a certs directory in your root path and setup a key-certificate pair there: - cert.pem contains the certificate, - key.pem contains the key pair.

Start Mailu

You may now start Mailu. Move the to the Mailu directory and run:

docker-compose up -d

Finally, you must create the initial admin user account:

docker-compose run --rm admin python admin root password

This will create a user named with password password and administration privileges. Connect to the Web admin interface and change the password to a strong one.