The Received: headers are instructive here. 

The mail is going through LISTSERV on the L-Soft Guava server, then 
sent to Gazelle at L-Soft which delivers it to some unnamed qmail 
server at 80.253.119.74 which then sends it back to LISTSERV on Guava 
where it is trapped as a repeat (thank goodness! otherwise you'd have 
had an infinite loop with every posting). Now you just need to do 
some investigative work to figure out which subscriber has the broken 
mailer that is sending the mail back to LISTSERV instead of 
delivering it to the subscriber.

80.253.119.74 is ns2.softflare.net. Do you have any softflare.net 
addresses in your list? If so, set them to NOMAIL and tell them that 
their mail server is broken. Otherwise, additional investigation may 
be necessary. The mail-merge suggestions will do the job, since they 
will reveal the actual subscriber address that is causing the 
problem, but you will have to get in touch with the LISTSERV admins 
(L-Soft in this case) to make sure that your LISTSERV node has mail-
merge enabled.

Francoise

> Received: from 80.253.119.74 by GUAVA.EASE.LSOFT.COM (SMTPL release 1.0m) with TCP; Fri, 6 Jan 2006 09:10:05 -0500 
> Received: (qmail 30919 invoked by uid 501); 6 Jan 2006 14:10:04 -0000 
> Received: (qmail 30915 invoked by uid 501); 6 Jan 2006 14:10:04 -0000 
> Received: by simscan 1.1.0 ppid: 30907, pid: 30912, t: 0.0989s
>         scanners: regex: 1.1.0 attach: 1.1.0 clamav: 0.87.1/m:34/d:1197 
> Received: from unknown (HELO gazelle.ease.lsoft.com) (209.119.0.5)
>  by 0 with SMTP; 6 Jan 2006 14:10:04 -0000 
> Received: from guava (guava.ease.lsoft.com) by gazelle.ease.lsoft.com (LSMTP for Windows NT v1.1b) with SMTP id <[log in to unmask]>; Fri, 6 Jan 2006 9:09:54 -0500 
> Received: by NETWORKS.IOP.ORG (LISTSERV-TCP/IP release 14.4) with spool id 1223
>          for [log in to unmask]; Fri, 6 Jan 2006 09:09:54 -0500 
> Received: from 193.252.22.157 by GUAVA.EASE.LSOFT.COM (SMTPL release 1.0m) with
>          TCP; Fri, 6 Jan 2006 08:59:30 -0500 
> Received: from me-wanadoo.net (localhost [127.0.0.1]) by
>          mwinf3112.me.freeserve.com (SMTP Server) with ESMTP id D03715800090
>          for <[log in to unmask]>; Fri,  6 Jan 2006 14:59:29 +0100 (CET) 
> Received: from wwinf3102 (wwinf3102 [172.22.158.29]) by
>          mwinf3112.me.freeserve.com (SMTP Server) with ESMTP id CBECA580008F
>          for <[log in to unmask]>; Fri,  6 Jan 2006 14:59:29 +0100 (CET) 

-- 
Francoise Becker <[log in to unmask]>

Knowledge is just a click away: http://www.lsoft.com/optin.html