Ione, I am not an "expert", but if I were you, I would do a Scan yourlist Pfizer to the listserv address, and see who is generating this error. If you are getting multiple errors of this nature from this person, then delete them. My listserv expert at Ummed has our 1400+ people list set up to pick up repeating errors, and it automatically dumps them. THis , I believe, is a result of some header information that instructs the listserv to delete folks whose addresses are bouncing. Kathleen Bruce Owner LACTNET, TLC [log in to unmask]