We were getting duplicate mail files here as well.  The problem appears
 to be related to the communications problems at node UGA.  It seems that
 when a VMNET link crashes, sometimes the sending node re-queues the file
 even though the receiving side thinks the transfer is complete.  So when
 the link re-starts, the same file is sent.  The connectivity problems at
 UGA were so bad that the same file was being sent over and over again.
 It was just a coincidence that Listserv was involved.  The people at UGA
 are aware that there was a problem.  I believe that their communications
 troubles have been resolved for the most part.
 
 -jj