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.
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.
