I am familiar with EL's high spam blocker which puts only whitelisted
mail into the inbox and EL-recognized spam in the spam folder and
everything else into Suspect. Its default setting also sends challenges
to the suspect From, which is a very bad idea, but that challenge system
can be turned off and the suspect folder managed sanely.
If I had a mail account which would benefit from such a whitelist +
suspect system and my operating system were windows and my mail agent
were Tb, I would probably use SpamPal as a proxy because it has an
excellent whitelist capability.
SpamPal was designed to be a very powerful and flexible blocklist agent,
with additional plugins for those who like such as Bayesian and regular
expression derived filters, but any part of its functions can be turned
off and/or configured.
The concept of a proxy like SP is that the mail which is coming from
your provider's server passes thru' the SP proxy where it is 'combed'
for the characteristic traits it is configured for, in this case its
whitelist of your contacts which go to the Tb inbox.
You could use it with a spam folder and a suspect folder, like EL's
system, except that the spam identification would be done by SP and
subject tagged as spam and a simple Tb filter for spam subject would
divert the SP-id/ed spam to the spam folder.
Everything which was not whitelisted (inbox) and not SP-spam (spam
folder) would be suspect folder.
--
Mike Easter