mailman3 3.1.1-9 (amd64 binary) in ubuntu bionic

 This is GNU Mailman version 3, a mailing list management system. This package
 provides the core delivery engine of the system, which handles the mailing
 lists data, receives messages, handles the moderation and processing of these
 messages and delivers them to the mailing lists subscribers. It communicates
 with the other components through a private administrative REST API.
 .
 Default database backend is SQLite3 in order to not break automated
 installations. For productive setups, PostgreSQL or MySQL are much better
 options though. See README.Debian for further information.
 .
 In order to get the full Mailman3 system, the metapackage 'mailman3-full'
 should be installed.