[Mailman-Users] endless reposting problem

[Gil Hardwick]

Wow,

Some of my clients had their office auto-responder switch on, and
their replies ended up running an endless loop through the system
so everyone else got 10-15 copies each before I had a chance to
turn it off.

I thought only a member of the list could post to the list, in this case
all moderated so I would have to approve all posts anyway.

If the list is not a member of itself, how can it keep posting the same
mail to and from itself in a continuous loop?

Is there something else I need to configure to stop this happening?

Gil