I just put a stop to a mail loop that was going on between our LISTSERV
and one of our other machines.  Here's the list header:
 
*
*  NHLBI NHBPEP Coordinating Committee
*
*  Review= Private      Subscription= By_Owner   Send= Editor
*  Notify= Yes          Reply-To= Sender,Respect   Files= No
*  X-Tags= Yes          Stats= Normal,Owner      Ack= Yes
*  Errors-To= Owners    Validate= Store Only     Mail-Via= Dist2
*  Filter= Also,*@NIHFAX
*  Notebook= Yes,E,Monthly,Public
*  Default-Options= Repro,ShortBSMTP
*
*  [log in to unmask] (xxxxxxx xxxxxxxx)
*  Owner= [log in to unmask] (xxxxxxx xxxxxxxx)
*  Owner= [log in to unmask] (xx xxxxxxxx)  <-- bad userid
*  [log in to unmask] (xxxxxxx xxxxxxxx)
*  [log in to unmask]@CU.NIH.GOV (xx xxxxxxxx) <-- 2 @s
*
 
(Userids changed to protect the guilty.)
 
I noted two problems with the Owner and Editor field above, plus there
are are spaces missing after the equal signs in 3 cases.
 
The loop started when a message sent to the list bounced.  As the list
is Safe= No, the message was sent back to the list name.  It was
identified as a delivery error and sent to the list owners.  The bad
owner userid bounced and the bounce message went back to the list,
rather than to [log in to unmask]  Apparently the envelope MAIL FROM
was the listname, rather than LISTSERV.  I've seen bad owner addresses
before, but never one that resulted in a loop this way.
 
Roger Fajman                                   Telephone:  +1 301 402 4265
National Institutes of Health                  BITNET:     RAF@NIHCU
Bethesda, Maryland, USA                        Internet:   [log in to unmask]
Postmaster for CU.NIH.GOV/NIHCU, LIST.NIH.GOV/NIHLIST, NIH3PLUS