http://msmvps.com/blogs/bgb/archive/2008/02/23/exchange-connection-filter-using-a-real-time-block-list-and-imfperfmon-msc.aspxHere are some things I do. I may miss a step so you may have to confirm things. After you added connection filter provider you need to make sure you have checked that stuff in the default virtual server. Global Settings/Message Delivery right click PropertiesenCommunityServer 2008.5 SP2 (Build: 40407.4157)