> These messages are  normally delivery errors. If you bounce  them back to
> the sender,  you're in fact  bouncing them back  to the mail  system that
> generated  the bounce,  which will  either reply  with another  bounce or
> throw them away. Only the list owner  can take action by deleting the bad
> address.
 
I'm confused.  I thought these bounces were caused by somebody including
old mail in a new posting and failing to edit out the list headers in the
old mail.  I thought listserv bounced them as a loop-preventive.  Why
would the original sender's mail system bounce (or throw away) the bounce?
 
Hmm.  I think maybe I've just thought of the answer.  Occasionally I see
that particular bounce message on delivery errors not related to a sender's
inclusion of unedited old list mail.  I bet that's what you're talking
about in your first sentence above -- although the ones I more often see
are the result of negligence of a subscriber, not a messed-up system.
   --Natalie ([log in to unmask])