Public bug reported: Hi, This bug report is little bit inaccurate. I had the following situation. I sent a message to Mailman 3 from mutt. I think that this message had no unixfrom header in "email.message.Message". The log file showed an exception thrown at "mailman/cure/runner.py". The exception "AttributeError: class MIMEMultipart has no attribute 'sender'" was caused because "_process_one_file()" of "runner.py" accesses "mailman.email.message.Message.sender" without any validation. The loaded, pickled file contained a "MIMEMultipart" object, the other one a "email.message.Message" as far as I can remember. I have attached a patch that ensures that "runner.py" is handling the expected Mailman "Message" instance but I think this was not the root of the problem. Hope it helps anyway. Best regards and keep up the good work on Mailman 3 ** Affects: mailman Importance: Undecided Status: New ** Tags: mailman3 ** Patch added: "Ensure runner.py handles a Mailman "Message" instance" https://bugs.launchpad.net/bugs/1333902/+attachment/4138396/+files/0003-mail... -- You received this bug notification because you are a member of Mailman Coders, which is subscribed to GNU Mailman. https://bugs.launchpad.net/bugs/1333902 Title: Mailman 3.0 goes awry when handling messages in an unexpected format To manage notifications about this bug go to: https://bugs.launchpad.net/mailman/+bug/1333902/+subscriptions