[Evolution] Filter Limitations?

[David Durham <david durham wcom com>]

Does anyone know of any limitations on the number of filters you can
have OR the number of rules within a single filter?

I've found that the filters don't seem to work if I put more than about
25-30 rules in a filter.. 

See, I get a LOT of spam on one certain account, and I have been
building this spam filter based on certain strings found in the message
body.  It has about 80 or 90 rules and I'm having to break them up in to
several filters, but even then it doesn't seem to work sometimes... 

How is the filtering code?... Is it thought to be buggy or stable?

I'm willing to work on it if necessary.  

I also have what I think would be a cool idea for filters.  One where
you can tell it to spawn another application which gets sent the whole
message text and can return 0 or 1 whether to filter it or not... Then,
for example, these existing spam filters which use intelligent huristics
to detect if a message is spam could be used with Evolution.  I looked
through what documentation I could find about Evolution to see if this
was already possible, but alas, I did not find anything relevant...

Thanks,
    -- Davy