This is a feature request.

I make extensive use of mail filters to filter spam.  I believe a very
useful filter would be "sender in addressbook/sender not in addressbook". 
This filter could be combined with other filters to make a very effective
spam blocker.


I know that filters can be combined, I have used almost every available
filter in the 20-odd filter rules I have created in evolution.  The one
filter that I wish I had would be "sender in addressbook/sender not in
addressbook".


One other thing: debugging filters can be very time consuming.  Have you
given any thought to a 'filter debugger'?  You know, something that would
single-step through each of the rules in each of the filters?  You could
make it part of a separate package, if you felt that you wouldn't want to
support it in the base install.  Just a thought.