To reproduce the error you need to enable topics for a list, create a topic and send a post that matches that topic.
You can do the enable/create by putting these two lines topics_enabled = 1 topics = [('Match_all', '.', 'Topic matches anything for testing', False)] in a file and running Mailman's bin/config_list like bin/config_list -i path/to/file/with/lines list_name Then, a post to that list should be delivered normally and contain a header 'X-Topics: Match_all', but the bug will cause the post to be shunted. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1251495 Title: Lists with topics enabled can throw unexpected keyword argument 'Delete' exception. To manage notifications about this bug go to: https://bugs.launchpad.net/mailman/+bug/1251495/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs