We intended to return mail that attempts to traverse PSUVAX1 from BITNET to UUCP. My concern is that most LISTSERV lists appear to put the list address in Sender: and Reply-to: headers and do not include an Errors-to: header. My mailer will dutifully send an error message back to one of these addresses. Which will be the original list if there is no Errors-to: header. My question is "What does a LISTSERV do with mail from 'mailer-daemon' or 'postmaster'?". If the answer is "Nothing special", there is a potential for swamping BITNET as these error messages are sent by LISTSERV to the original 'bad' addresses on the list. I can munge the return address to send it back to POSTMAST@WHEREVER instead of LISTNAME@WHATEVER if this is the case. Anyone have any thoughts or suggestions? Thanks. -- Dan Ehrlich - Sr. Systems Programmer - Penn State Computer Science <[log in to unmask]>/Voice: +1 814 863 1142/FAX: +1 814 865 3176