Are you aware of any false positives of LISTSERV standard duplicate checking? From: "L-Soft list server at LISTS.PSU.EDU (1.8d)" <[log in to unmask]> Subject: Rejected posting to [log in to unmask] To: <[log in to unmask]> Your message is being returned to you unprocessed because it appears to have already been distributed to the psulist list. That is, a message with identical text (but possibly with different mail headers) has been posted to the list recently, either by you or by someone else. If you have a good reason to resend this message to the list (for instance because you have been notified of a hardware failure with loss of data), please alter the text of the message in some way and resend it to the list. Note that altering the "Subject:" line or adding blank lines at the top or bottom of the message is not sufficient; you should instead add a sentence or two at the top explaining why you are resending the message, so that the other subscribers understand why they are getting two copies of the same message.