If you are having problem with receiving too much spam email in your outlook email.
You might want to check this anti-spam plugin for outlook. It helps filtering out incoming email that potentially be spam email. The program is clever enough to improve along the way if you trained them.

SpamBayes will attempt to classify incoming email messages as ’spam’, ‘ham’ (good, non-spam email) or ‘unsure’. This means you can have spam or unsure messages automatically filed away in a different mail folder, where it won’t interrupt your email reading. First SpamBayes must be trained by each user to identify spam and ham. Essentially, you show SpamBayes a pile of email that you like (ham) and a pile you don’t like (spam). SpamBayes will then analyze the piles for clues as to what makes the spam and ham different. For example; different words, differences in the mailer headers and content style. The system then uses these clues to examine new messages.

I have use this anti spam filter for some time now, I find it quite good.
You can get further info and download it from spambayes.