The following error delivery notice caused a mailing loop on JHUVM's
 Listserv over the weekend.  I've send a note to the postmaster at
 att.com and att.att.com asking for their cooperation in developing
 a way to stop future occurences of this problem.  If any of you
 have mailing lists which utilize the att.att.com gateway machine,
 keep an eye on them.  I don't know if this is a newly implemented
 format for mail delivery errors, or if the conditions that cause it
 to be used are rare.  Listserv eventually caught the loop once the
 "From:" line mutated to [log in to unmask] (it was xxuucp and inuucp
 at various times during the loop).  Since the original posting wasn't
 included in the error message and the "Subject:" is innocuous, the
 mail got passed all the triggers.
 
 -jj
 
 -------- sample error message from att.att.com follows:
Received: by JHUVM (Mailer R2.08 PTF008) id 8028; Sun, 12 Apr 92 13:38:37 EST
Date:         Sun, 12 Apr 1992 13:32:00 EDT
Reply-To:     4ad recording artists list <[log in to unmask]>
Sender:       4ad recording artists list <[log in to unmask]>
From:         [log in to unmask]
Subject:      UUCP Mail
To:           Jim Jones <[log in to unmask]>
 
UUCP request att!D.att6dc2fe2 to emsp!D.att6dc2fe2
failed on system 'emsp'.
Reason for failure:
        remote system can't create temp file
        remote file system is low on free space