In case you were wondering why it was so quiet here lately: I didn't know that Debian Bullseye removed Mailman 2.1 - and when I dist-upgraded the server, the mailing lists stopped working.
Unfortunately, it wasn't trivial to setup Mailman 3. The install documents were missing some important steps, the Debian setup also had a few bugs and as I am using Postfix with virtual domains, some extra work was needed.
However, it seems to be working again now, let's continue fixing the remaining issues :)
You can access the mailing list and change your subscription options here: https://www.pyra-handheld.com/mailman/
Let me know if something isn't working right for you.