Jim, I'm not surprised that LISTSERV could not detect that mail as an error message. It is not from anything recognizable as a mailer daemon and does not contain anything else to trigger any of LISTSERV's error message detection code. I would suggest that you SERVE ... OFF the address returning the error ([log in to unmask]). That should prevent the loop from continuing. Mark R. Williamson, Rice U., Houston TX; [log in to unmask] or @RICEVM1