Hi BC,
You coule use a product such as ClearMyMail (
www.clearmymail.com) - which is a 100% successful anti-SPAM system. Prices for a single user licence are from £2/month and it's a very good product.
Come back to me if you're interested, and I can arrange a free 14-day trial for you. If you contact them directly through the web site, please mention my name (Dan Stuchbury @ Stuchbury Associates).
Hope this helps, and good luck SPAM-busting!
Kind Regards,
Dan Stuchbury