Please note, Plesk has supported the version of Mailman provided by OS vendor by default.
The Mailman 3 is shipped by default on Ubuntu 18 and Debian 10.
Please keep voting if this request is still actual for you.
AARae supported this idea ·Rae commented
Please add Mailman 3 as an installation option. We have been waiting for this for a very long time. Mailman 2.1 is old software and doesn't have the dkim options to keep the lists from being blocked. Migrating Mailman 2.1 lists to Mailman 3 won't be too overly difficult if we give our customers a choice. The main issues of migration would be the archives but since MM 2.1 stores them as HTML that is fine for our customers to just shift over to Mailman 3. Many have been requesting this upgrade for many years now. Please, let's get this done.