> One of the lists on our server is sending duplicate messages to > subscribers. The messages appear in the archives and in subscriber > mailboxes with identical time and date stamps. I have confirmed in the > LISTSERV log that it is actually sending the message twice not the SMTP > server causing the duplicate distribution. You have a subscriber who's gateway is "reflecting" the message back to LISTSERV rather than bouncing it according to standards. Looking at the full headers of the duplicates should give you a clue on who this subscriber is. You will notice in the archives, each duplicate message has an additional 6 lines of text. The is the additional received headers which will point to the offender.