All of these "solutions" still mean you have to download the email... and if you get as many as I do.. that is gonna be significant BW over time.
MailWasher 4.0 -
deletes from server,
can automatically delete SPAM(from server),
compares incomings to SpamCop/ORDB,
can automatically report to SpamCop,
can bounce spam,
blacklist/whitelist,
doesnt add anything to email messages
essentially unlimited filters,
learns as it goes spam/ham
Easy setup,
Free trial,
< $40.00
it is the only thing close to an answer that I know of
http://www.firetrust.com/products/pro/