[I'm tempted not to answer because I am reinforcing the bad behaviour of
resubmitting queries to the list]
Places I would look:-
* The passed over message is a bounce. Have you got any special
handling for null senders?
* Is NFS involved? Could the forward file not be accessible
temporarily.
* Are you detecting on subject (or other) headers? If so could
there be multiple headers (which might be collapsed on
delivery).
* If its not on subject headers, could the subject and tagging
headers disagree (particularly likely to be the case on bounces
where the original subject was tagged, and the bounce generated
later).
Additionally you appear to be doing scan and reinjection spam handling.
Are you sure thats a good idea?
Nigel.
--
[ Nigel Metheringham Nigel.Metheringham@??? ]
[ - Comments in this message are my own and not ITO opinion/policy - ]