Exchange 2003 & Spam

Hello,

I currently have a Exchange 2003 server setup with the IMF filter turned on. The spam filter works great, low false positives and it is very effective.

Yet the share volume of spam the server is receiving is very large (95-99% of all emails received are spam). Is there anyway to configure the exchange server to reject emails from dynamic IPs. Since the vast majority of spam generally comes from “bot” networks I figured this would be a great way to diminish the volume of spam received everyday.

Thanks for the help,
Bill