Have you tried finding alternate ways of giving your email address other than the standard mailto:example@.example.com syntax? Pretty well all spam bots can read these addresses and use them to spam the crap out of you. You can try rewrite the address or use a javascript or php technique to hide it from bots. There is a good article here:
http://www.maurits.vdschee.nl/php_hide_email/You may also want to invest into some good old spam filters for outlook. Personally I use webmail so I have no experience with outlook spam filter software, but I think my fathers business uses a program called spamfighter.
http://www.spamfighter.com/ and Trend Micro anti-spam. I'm not sure as to the effectiveness of these products though.
Good luck, spam is unbelievably annoying
