[Design] filters: req for filter condition "is in address book X"

[Kaitlin Duck Sherwood]

A filter condition that I find extremely useful is "is in address 
book X".  For example,
	if incoming message sender is in address book named "Friends"
	then assign message to category "Friends"

When that filter condition doesn't exist, I end up making long lists 
of filters:

	if incoming message sender is mabel@flossrecycling.com
	then assign message to category "Friends"

	if incoming message sender is jenny@pigpals.com
	then assign message to category "Friends"

	if incoming message sender is loretta@facelessentity.com
	then assign message to category "Friends"

etc.

There should be late binding on the address book.  If I add Eduardo 
to my "Friends" address book, I want subsequent messages from Eduardo 
to end up with the "Friends" category.  (Outlook 2000 has early 
binding and it is a real pain!)

Note that I don't care how this is implemented exactly.  If there is 
one address book, but people in it are grouped by an attribute named 
"Group", then a filter condition "has Group attribute X" is fine by 
me.

-- 
Kaitlin Duck Sherwood
Author of the _Overcome Email Overload_ series, http://www.EmailOverload.com