It looks like the exim "pipe" command
http://www.exim.org/exim-html-4.50/d....html#SECT3.13
could send the incoming forwarded bayes training ham or spam through a sed or similar script that could delete everything up the, at least in my forwarding-from-yahoo client case,
Content-Type: message/rfc822
and the blank line required to be following it.
The script will then need to, I think, delete any prior SA X-Spam headers, too.
The script will have to be able to detect different forwarding clients and handle them each a bit differently, I believe.
(I gotta add a section to the script delete the forwarding persons signature, too...)
Does any of the above make sense for me to start working on, or am I wasting my time?
Thanks,
Pete