I'll go ahead and put a bug in your ear just in case you get more people reporting duplications of Listserv messages. Recently I had an issue where our Listserv server was periodically duping messages. It started small at first, one report of a dup which couldn't be substantiated, but then it was like every other day dups were occurring. When I reviewed the i-headers of both messages in the dup (sometimes three messages spread over a couple of days) I found that Listserv itself wasn't creating the dup, but external SMTP servers. Now at the time we were forwarding all messages from Listserv directly to an external SMTP gateway round-robin we have setup and only using LSMTP for inbound connections. It would connect to different SMTP servers, deliver the message, and then those servers would try and connect to foreign email systems and deliver the message (normal process). But then inexplicably, the SMTP gateways would connect again a day or so later and deliver the message again. I checked the SMTP logs and noticed that the sessions from the SMTP gateways were starting out ok to the foreign email systems but were not getting an appropriate 250 completion code from the foreign email system, failing out, and then trying again when the retry timeouts came up (these are normally like 30 minutes, 1 hours, 4 hours, 1 day, and 3 days approx.). I went into LSMTP and changed the MAXBSMTP config variable from 100 (default) to 50 so that Listserv would split up the number of recipients on an email into smaller chunks. Also, our SMTP gateways were tuned back to only allow 50 emails per connection. That helped the gateways from being so busy all of the time processing a single connection that they might drop connections and have to resend the message. Anyway, this may not be your problem cause a dup could be a lot of things and as others have said, you really won't be able to begin troubleshooting the problem unless you can get samples of the i-headers from both messages in the dup, but just in case you come across increasing dups like I described above, I hope my experience with this helps. Jeff Lobaugh CDC Information Technology Support Contract (CITS) Business Computer Applications, CDC/ITSO Network Specialist Wk. (404) 639-7632 Fax. (404) 639-7848 -----Original Message----- From: LISTSERV site administrators' forum [mailto:[log in to unmask]] On Behalf Of Gilmore,Mindy Sent: Thursday, May 06, 2004 2:55 PM To: [log in to unmask] Subject: wits end I am at my wits end trying to troubleshoot a user that says a message they send to the list two days ago went out again all by itself. Can anyone point me in the right direction, or tell me what might cause this.