One thing I forgot to mention: a week ago, the confirmation-mails still worked.
And now: All attempts to confirm the subscribe message failed. I used the list-request@list.domain and sent text-only message with the "confirm token" in the subject and/or in the body.
So today I tried and used the Mailman shell to change the pending state to "confirmed", as you described here: https://lists.mailman3.org/archives/list/mailman-users@mailman3.org/thread/6... After I submitted the command util.confirm('hex_token') and restarted mailman with mailman stop mailman start the pending user wasnt confirmed but cleared, as if he never sent a subscribe-message. The only way to subscribe seems to be by logging in and using there the subscribe-form. Do you have any idea, whats going wrong here? I dont know what to do any more. Thank you :-) Wolfgang