We have been testing XA for months and are hoping to go live tomorrow :-)
Every once in a while (about 1 out of 100?) listserv will replace the
Date: tag with the next line in the file (normally the Reply-to:).  We
are running XA 2.1 and CMS 5.0.  We have spotted this behaviour on DIST
jobs from only about 5 lists (ANTHRO-L, BIRDCHAT, CHRISTIA, EDPOLYAN).
Most mail from these same lists is processed just fine. Any help or
suggestions would be greatly appreciated.
 
Below are the original DIST2 Job and the resulting MAILER rejection (note
that the Date: was replaced).
 
>//ANTHRO-L JOB Echo=No,Reply-to="ANTOWNER@UBVM"
>//To DD *
>deleted
>/*
>// DIST2 MAIL FROM=ANTHRO-L@UBVM I=Y FORW(CRC) HOST(214 214)
>//Via DD "UBVM USCVM"
>//CRC DD "1-526E0165"
>//Data DD *,EOF,Res=Disk
>Date:         Thu, 14 Nov 1991 21:31:00 CST
>Reply-To:     General Anthropology Bulletin Board <[log in to unmask]>
>Sender:       General Anthropology Bulletin Board <[log in to unmask]>
>From:         deleted
>Subject:      deleted
>To:           Multiple recipients of list ANTHRO-L <ANTHRO-L@UBVM>
>
>text deleted
 
 * * * *produces the following rejection * * * * * * * * * * * * *
 
>Date: Fri, 15 Nov 91 07:17:50 PST
>From: Network Mailer <MAILER@UVVM>
>Subject: Undelivered mail
>To: (our MAILER Maintainer)
>----------------------------Original message----------------------------
>Your mail was not delivered to some or all of its
>intended recipients for the following reason(s):
>
>Required DATE is not present.
>Error loop detected.
>Another network mailer sent an invalid file.
>
>--------------------RETURNED MAIL FILE--------------------
>Received: by UVVM (Mailer R2.08 R208004) id 0356; Fri, 15 Nov 91 07:17:51 PST
>Reply-To:     General Anthropology Bulletin Board <[log in to unmask]>
>Reply-To:     General Anthropology Bulletin Board <[log in to unmask]>
>Sender:       General Anthropology Bulletin Board <[log in to unmask]>
>From:         deleted
>Subject:      deleted
>To:           deleted
>
>text deleted