Spam Bully is a spam filtering solution that integrates into Outlook. Spam Bully utilizes an advanced Bayesian filter system based on thousands of spam messages. It learns from every email message you send and receive. This way it learns what you consider spam and what you consider acceptable email.
There's a special Friends/Spammers list; so your friend's emails are never
blocked and messages of known spammers are automatically designated as spam.
Query emails can be sent to unfamiliar emailers with a special message
requiring them to respond before they are added as an accepted users. All
features are fully customizable to meet your own needs.

Give it a try at:

Top 5 bug reporters will receive a free copy of the final version.