We have been trying to track down the problem, to no avail so far. Here is what is happening to the best of my knowledge: 1. Mailer (lmail) gets a file from listserv. 2. It adds its Received: header and passes it on to SMTP 3. SMTP receives the file, adds its Received: headeru 2d passes it on. THEN STEP 3 OCCURS AGAIN, FREQUENTLY MANY HOURS LATER. What I've been asking for is copies of the headers from each of the duplications. Just one set isn't enough. I need to see the Received: tags from the duplicates to even have a chance of tracking it. We've called the problem in to IBM, but they have no record of this type of problem with SMTP.