One of my subscribers keeps sending automated messages to the list, resulting in a loop. How do I stop it?

If your Mailman list is set up as a discussion list, it's possible that one of your subscribers might accidentally cause some kind of never-ending loop, resulting in a flood of messages that need to be stopped.

For example, we've seen situations where people mistakenly set up mail forwarding to forward a copy of each message back to the list posting address. We've also seen people using poorly-designed software that sends "out of the office" messages back to the list posting address. In either case, every list message that this person receives will cause a new list message to be created, and you'll have to take action to stop the resulting flood of messages.

Solving the problem

There are a number of ways to handle this.

If you know which list member is sending the messages, do one of the following:

If you can't determine which member is sending the messages, you can temporarily turn on the Emergency moderation of all list traffic option in Mailman's "General Options" screen. This prevents any messages from being sent without your approval.