I have a need for mailman, however I'm unclear on some things. I see that mailman 2 is not supported on Debian anymore and has been replaced by mailman3. I also see a couple of posts from 2023. One suggests mailman3 is not and likely will not be supported by ISPConfig, the other suggests it will be added. I can't find any more information on the subject and am wondering if mailman3 is currently supported on ISPConfig or if it is still only mailman2.
Mailman 2 is not available on the latest Ubuntu/Debian releases. ISPConfig does not support Mailman 3. Mailman 3 and ISPConfig can coexists on your server, but you will not be able to manage mailman through ISPConfig. What might be possible is to build Mailman 2 from sources and use it, although i would not recommend that.
Have you ever managed to install a Mailman 3 alongside ISPConfig? I go crazy trying to do that, especially because there seem to be some remnants of the previous Mailman 2 support in the postfix main.cf...
I do not use Mailman at all. I don't think that i would install it on my ISPConfig mailserver in your situatuion, but rather use a seperate VM/Container for this. This part alone would be too much of an headache to maintain properly. Not worth the hassel IMO.
I would most likely just dockerize the whole setup. So mailman-core, mailman-web and a MTA in Docker. Or depending on how much control/customization i need i would use a LXC or small VM.
