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:
- Completely unsubscribe that member, which prevents the member from receiving or sending any list messages. This is the safest method.
- Turn on the moderation (mod) checkbox for that member in Mailman's "Membership Management" screen. This prevents the member from sending any new messages to the list.
- Turn on the nomail checkbox for that member in the same screen, which leaves the member subscribed but prevents him or her from receiving any list messages until you uncheck the box. This may be appropriate if the member is sending "out of the office" autoreplies (it's easier to undo this change when the problem is solved than if you completely unsubscribed the member).
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.