> >Recently I've been getting two copies of space digest one right after >the other. The copies are identical, but I don't always get two of >each. A TRACK snapshot of the listserv console output is included >below. Is this the proper place to report possible duplicate mailing? >The Space Digest issue in question is Vol 9 issue 74. If the digest originates on the Internet, there is a possibility of duplication by SMTP. RFC 1047 by Craig Partridge, "Duplicate Messages and SMTP" (2/88) describes the problem. (You can get the RFC in LISTING format from LISTSERV@TCSVM as RFC1047 LISTING in the RFC filelist). The problem occurs more between some pairs of sites than others. Basically the problem is that one system accepts the mail but does not confirm it with the other system before the connection is severed. So the sending system will resend the mail later. Several factors and remedies are discussed. For example, I think the RFC has influenced some of the design changes in IBM's SMTP server (current and/or future...). The most useful thing I have found to track down the problem is simply sending the LISTSERV distributing the list to me the SET listname FULLHDR command. You can easily compare the "Received:" lines for the point at which the times differ. It is that connection which is creating the duplicate. In the past the duplicates, when they occured, came on the same connection each time. Of course they didn't always appear and it would be possible to get more than two copies. Your results may differ. Different in California... :-) ----------- Marty Hoag ND Higher Education Computer Network US Mail: NDSU Computer Center Phone: (701)-237-8639 PO Box 5164 / UCCS Bitnet: NU021172@NDSUVM1 (NOTE 0 = ZERO) Fargo, ND 58105 Internet: [log in to unmask] UUCP: ...!psuvax1!NDSUVM1.BITNET!NU021172