Hi, I am new to the list but old to the LISTSERV :-) Lately I have been banging my head against the following problem. I would very much appreciate any ideas, no matter how wild they might seem. What happens: I have mostly local subscribers, but some are from outside domains like gmail, hotmail and yahoo. One of the outside domains is our university central mail system (our department is running its own mail system). Subscribers, whose addresses are in the university central mail system intermittently receive list posts duplicated. I traced the problem in the logs and here is an example of what happens: 1. At 17:17:28 <poster> sent the mail to [CHEMMAIL] list. 2. at 17:20:34 LISTSERV received the approval confirmation from <poster> for [CHEMMAIL] list. At 17:30:34 (standard 10 minutes delay) the LISTSERV created a list of all recipients, put them into 8 outbound files, confirmed the mailing to <poster> and closed the operation. All addresses were on the list only once. 3. From 17:30:34 to 17:30:35 LISTSERV passed those outbound files to sendmail via 127.0.0.1: Log: Mar 26 17:30:34 alchemy sendmail[7515]: n2QIOWrX007515: from=<[log in to unmask]>, size=6912, class=-30, nrcpts=100, msgid=<[log in to unmask]>, proto=ESMTP, daemon=MTA, relay=localhost [127.0.0.1] Mar 26 17:30:34 alchemy sendmail[18730]: n2QKH6dP018730: from=<[log in to unmask]>, size=6912, class=-30, nrcpts=6, msgid=<[log in to unmask]>, proto=ESMTP, daemon=MTA, relay=localhost [127.0.0.1] Mar 26 17:30:34 alchemy sendmail[7515]: n2QIOWrZ007515: from=<[log in to unmask]>, size=6912, class=-30, nrcpts=100, msgid=<[log in to unmask]>, proto=ESMTP, daemon=MTA, relay=localhost [127.0.0.1] Mar 26 17:30:34 alchemy sendmail[7515]: n2QIOWrb007515: from=<[log in to unmask]>, size=6912, class=-30, nrcpts=100, msgid=<[log in to unmask]>, proto=ESMTP, daemon=MTA, relay=localhost [127.0.0.1] Mar 26 17:30:34 alchemy sendmail[7515]: n2QIOWrd007515: from=<[log in to unmask]>, size=6912, class=-30, nrcpts=100, msgid=<[log in to unmask]>, proto=ESMTP, daemon=MTA, relay=localhost [127.0.0.1] Mar 26 17:30:35 alchemy sendmail[18730]: n2QKH6dR018730: from=<[log in to unmask]>, size=6912, class=-30, nrcpts=100, msgid=<[log in to unmask]>, proto=ESMTP, daemon=MTA, relay=localhost [127.0.0.1] Mar 26 17:30:35 alchemy sendmail[7515]: n2QIOWrf007515: from=<[log in to unmask]>, size=6912, class=-30, nrcpts=100, msgid=<[log in to unmask]>, proto=ESMTP, daemon=MTA, relay=localhost [127.0.0.1] Mar 26 17:30:35 alchemy sendmail[18730]: n2QKH6dT018730: from=<[log in to unmask]>, size=6912, class=-30, nrcpts=100, msgid=<[log in to unmask]>, proto=ESMTP, daemon=MTA, relay=localhost [127.0.0.1] 4. At 17:31:13 the message was accepted for delivery by smtp2.ns.utoronto.ca Log: Mar 26 17:31:13 alchemy sendmail[26418]: n2QIOWrf007515: to=[list of users nuked], [more], delay=00:00:38, xdelay=00:00:38, mailer=esmtp, pri=3150912, relay=smtp2.ns.utoronto.ca. [128.100.132.58], dsn=2.0.0, stat=Sent (n2QLUZ6e021353 Message accepted for delivery) 5. At 17:41:38 LISTSERV sent again one block of addresses with the same message ID but different sendmail ID. Log: Mar 26 17:41:38 alchemy sendmail[4738]: n2QLfbdg004738: from=<[log in to unmask]>, size=6912, class=-30, nrcpts=100, msgid=<[log in to unmask]>, proto=ESMTP, daemon=MTA, relay=localhost [127.0.0.1] 6. At 17:42:05 the message was resent to all UTORmail recipients in 4 blocks of addressees identical to the previous blocks of addressees. Log: Mar 26 17:42:05 alchemy sendmail[4746]: n2QLfbdg004738: to=[list of users nuked], [more], delay=00:00:28, xdelay=00:00:27, mailer=esmtp, pri=3150912, relay=smtp2.ns.utoronto.ca. [128.100.132.58], dsn=2.0.0, stat=Sent (n2QLfmRs024838 Message accepted for delivery) It seems clear that the bifurcation occurs at the LISTSERV -> sendmail level. However, there is no trace of that in the LISTSERV log. The last entry in that log is 17:30:34 (send job finished) followed by an unrelated entry at 18:38:53. Thanks Frank -- Frank Bures, Dept. of Chemistry, University of Toronto, M5S 3H6 [log in to unmask] http://www.chem.utoronto.ca PGP Public Key: http://subkeys.pgp.net:11371/pks/lookup?op=index&search=Frank+Bures Please, reply to the above address only. <lisfrank> does not accept replies.