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.