You could try a spam blocker, also never type in your email address anywhere unless you trust its a friendly website, and always tick the "don't send me info" buttons when registering on sites.
Personally I find Outlook 2003 does a good job, however you may wish to use a tool like "mail washer" or something.
You could also change your email address, get a hotmail or gmail address or something.
Also you may find that your on somebody's address book who has a virus thats kicking out emails to everybody on there address book including you (generally this will be the case if your getting 40+ a day and they're all the same but from different addresses)
hope this helps