I  think one  of  the sites  involved  has a  mailer  which rewrites  the
'Sender:' field  to have an  Internet-style address. The peering  code in
1.7d can't handle  that. With 1.7e mail is sent  to peers via DISTRIBUTE,
which bypasses the local mailer. The  only solution I can offer right now
is to send the  beta 1.7e code to the site which  rewrites the header, if
they agree to run it.
 
  Eric