>Since when are mail messages coming back to listserv telling you
>that the mail has sucessfully made it to its destination?
 
>I have never seen this before, but I certainly don't hope its common.
 
Write an e-mail to the postmaster/root at that host explaining how
you receive these for list distributions and that it is both
a waste of bandwidth and your time to process these.
 
Also imply that if it continues, you will have absolutely no
choice but to unsubscribe the user since this is non-standard
behaviour for your list participants.
 
/Pete