This is GNU Mailman, a mailing list management system distributed under the terms of the GNU General Public License (GPL) version 3 or later. Mailman is written in Python which is available for all platforms that Mailman is supported on, including GNU/Linux and most other Unix-like operating systems (e.g. Solaris, *BSD, MacOSX, etc.).
You must [configure the admin user](http://docs.mailman3.org/en/latest/config-web.html#setting-up-admin-account):
```bash
$ cd /usr/share/mailman3-web
$ python3 manage.py createsuperuser
```
You should then attempt to log in with this user account in the web UI. Once you've logged in, a confirmation mail will be sent to your email address that you specified. Therefore, you should have something like [Rainloop](https://github.com/YunoHost-Apps/rainloop_ynh) installed to view mail on your YunoHost installation.
Mailman3 implements an LMTP server for receiving mail from Postfix. This means that Mailman3 doesn't need anything from Dovecot. This is important to understand because Dovecot is the default YunoHost local delivery agent. Therefore, the default YunoHost Postfix configuration uses Dovecot. So, in order to deliver incoming mail, we need to override which delivery agent handles which mails based on the addresses. In other words, if you create a mailing list "mylist@myyunohost.org" you want Mailman3's LMTP server to receive this, *not* Dovecot, becaues Dovecot only delivers to LDAP created user accounts.
You'll need to add this to your Postfix configuration:
This is unfortunately a manual step at this point because the package remains experimental. Once it matures, this will be integrated into a hook or the default Postfix configuration. For now, remember that when you run `yunohost tools regen-conf postfix` or if any installation invokes `regen-conf`, your Postfix configuration will not be changed because it has diverged from the default configuration. This may cause you problems if YunoHost core expects that there is some new value in your Postfix configuration.
There is also documentation for "the suite" which is all the parts together:
* https://docs.mailman3.org
On your YunoHost, all the configuration files you need to worry about are in:
*`/etc/mailman3/`
It is important to note that this package makes use of the [mailman3-full](http://docs.mailman3.org/en/latest/prodsetup.html#distribution-packages) Debian package contained in the Debian Stretch backports repository.
