[Mimedefang] Caching the results of a SpamAssassin scan

[Joseph Brennan]

  According to the mimedefang-filter man page, $RelayAddr is
> not  available in filter_end, where the SA scan takes place.


This is test code too.  Maybe it's not going to work.  If it does
not, I have to find another way to exempt those messages.

Joseph Brennan          Columbia University in the City of New York
postmaster at columbia.edu                 Academic Technologies Group