I would try Spamnet rather than the above. They charge just over a £1 a month and don't download your email but just removes the offending email from your inbox. The database is composed of their research and from feedback from all spamnet's 1,000,000 users. When a spam is not automatically caught you
mark it as spam. This then informs spamnet and with enough votes globally classes it as spam so that it is captured in everyone's inbox.
Works well and captures about 98% of your spam.
You can try it for 30days.
http://www.cloudmark.com/products/spamnet/