Martin Lorenz writes:
so I had to switch to a new provider. The new v-server is debian-based. the release is bullseye which does still provide python2 but lacks a few packages that are necessery to install mailman2.1 I would have to manually install dependencies via pip instead of apt.
As long as you have necessary access to install, that should not be a problem.
The problem occurs whenever mail ist sent to a migrated list. All mails sent to the lists I migrated from my old 2.1 instance (23 lists in total) are swallowed and never get delivered.
That sounds a lot more like MTA configuration problems or network configuration problems than resource usage.
I have not found out where they are.
IIRC Debian puts queues in /var/lib/mailman3/queue/. Look in ../shunt in particular (that queue swallows posts that for some reason Mailman is unable to process, and you have to do something to fix the problem -- there's no automatic retry for those).
There are no errors in the logs.
Which logs are you looking at specifically?
1 was only because I quickly needed a working solution - which I did not get.
Unfortunately, I don't know of a quick working solution from any OS distro. All the distros either provide very old versions, or we have reports of difficulties configuring them. The closest thing to a turnkey solution are Abhilash's docker containers, but even there it's non-trivial. My recommendation (FWIW, now that you've already gotten started it may not make sense to start over from scratch) is that you get yourself a nice stable distro with at least Python 3.8 (better 3.9 or 3.10) installed, browse both the "venv" installation described in our docs at https://docs.mailman3.org/en/latest/install/virtualenv.html and Brian Carpenter's Debian installation guide at https://wiki.list.org/DOC/Howto_Install_Mailman3_On_Debian10. Then choose the guide you find more compatible with your thinking, and follow that.
thank you for the help you offer. The time I can invest on the subject is rather limited for the coming week. from Oct. 14 on I can dive into it :)
OK, no hurry. We'll be here when you're ready.
Steve