Turgut, For clarification. Did you infer that LISTEARN will be modified to check for various subject line strings to determine if the mail is from a mailer or somesuch. In particular, does it handle PMDF mail which defaults to sending a mail message to the sender (LISTSERV) for each message telling him that he could not deliver the mail within 3 days so will try again for the next 9 (or whatever). If LISTEARN decides not to put such a message to the list (good idea) can it be set so that it will 'black hole' the mail rather than bouncing it to the postmaster. How do other sites handle this? Thanks, Dermot O'Beirne UCD, dublin