Question Mailman3 with plesk

[Larian]

Server operating system version

Debian 12

Plesk version and microupdate number

18.0.61 Update 1

After updating from Debian 10 to 11 to 12, I now have mailman3 running on my server
I then converted all lists from Mailman2 to Mailman3 following the instructions from mailman.
I can access it via the web interface, manage everything etc.
When I register on the web interface, I also receive the corresponding mails from Mailman (forgotten password...)
Mails are also arriving, at least mails that are not allowed go into the mails to be approved.

The problem, however, is that it does not send out any mails, nor do they appear in the archive.

When I look in the Mailman-Log I find:

May 16 01:44:55 2024 (6833) Cannot connect to SMTP server localhost on port 25
May 16 01:48:15 2024 (61252) error opening connection to nntp_host: localhost
[Errno 111] Connection refused
May 16 01:48:15 2024 (61252) NNTP error for list [email protected]:
[Errno 111] Connection refused

The configuration of Mailman.cfg looks like this:

incoming: mailman.mta.postfix.LMTP
outgoing: mailman.mta.deliver.deliver
smtp_host: localhost
smtp_port: 25
smtp_user:
smtp_pass:
lmtp_host: 127.0.0.1
lmtp_port: 8024

In Mailman manuals I find hints that the transport routes have to be added to the Postfix-config. Doesn't Debian/Plesk do this automatically?

Does anyone else have an idea what I need to change to get my mails out?

I did the conversion from mailman2 to mailman3 with root because it didn't work with "sudo -u list "m, but the files stored in the file system all belong to list, so that shouldn't be the problem.

 

[Larian]

Seems nobody can help?
Does anybody know where Plesk stores the mailroutes for postfix? The aliases-file is empty?

Mailman 2 must have already stated somewhere which mails are routed via mailman and how?