I'd love to see such a tool. A problem that I've seen in
doing that is that many times the bounce messages are only a
once or twice happening then go away. ie user experimenting
with new mail handler at same time as a list message is sent.
Depending on your list and how many addresses are in the list
that are also exploders, there is also a problem of what
really IS the failing address? Also what to do about those
stupid UUCP status replies that come in.
Along the same lines, has anyone done a "-request" addressed
message to majordomo formatted request? It shouldn't be that
hard, but if someone has already one it... In this way people
that are used to the list-request address don't have to learn
a new system.