Vista - Spam Filtering

My main security suite (Kapersky 7) has a spam filtering facility. When it
detects incoming mail from an unknown (hence untrusted) sender it pops up
and asks me what to do, so it knows who I regard as good guys and bad guys.
But, there's always a but, it only works on POP3 mail not on things like
Hotmail and Gmail - and you can guess where 99,9% of my spam comes from. I
quite like having spam filtering happening at the front gate rather than at
the front door. I think K7 can put mail from bad guys straight into the bit
bucket - i.e. no junk mail folders. I don't want to move the function out
to my ISP (they also can only do anything about POP3 accounts) or to the
HotMail and Gmail hosts because I would have to maintain 3 systems.

Does anyone know of any products that will monitor incoming mail from POP3,
Hotmail, Gmail and presumably other web based mail systems, e.g. Yahoo; at
the front gate and that wont interfere with the smooth operation of WLM or
K7.

I don't want to write filters in WLM because IMO that's too late, the stuff
is in and its on a disk - whereas the a front gate filter looks at sender
details before mail is fetched from server.