All, Here's my current setup. I have a FE/BE Exchange 2003 SP2 with a separate DC/GC server in the environment. I've followed the RPC-HTTP using KB from Microsoft and I've setup the RPC setup on the System manager to designate the FE/BE structure. I haven't enabled SSL yet because I want to test the basic functionality of the RPC/HTTP Outlook before I enable SSL. I've opened up the necessary ports on the firewall. (The RPC Proxy is sitting behind the firewall) So I opened up ports 6001, 6002, 6004 along with the 80/443 for the Proxy server. On the Outlook client, I've unchecked the "Connect using SSL only" box. I hit OK and OK and when I click on the "Check Name" box, I get the Connecting to my BE server with a username and password box. I put in my username and password (both FQDN name and email address) and it does not authenticate. Here is what I'm seeing on the IIS log on my FE box. 2006-02-28 17:20:55 W3SVC1 10.5.1.27 RPC_IN_DATA /rpc/rpcproxy.dll beserver.mail.com:6002 80 - 70.21.123.227 MSRPC 401 2 5 2006-02-28 17:20:55 W3SVC1 10.5.1.27 RPC_OUT_DATA /rpc/rpcproxy.dll beserver.mail.com:6002 80 - 70.21.123.227 MSRPC 401 2 64 2006-02-28 17:24:04 W3SVC1 10.5.1.27 RPC_IN_DATA /rpc/rpcproxy.dll beserver.mail.com:6002 80 - 70.21.123.227 MSRPC 401 2 5 2006-02-28 17:24:04 W3SVC1 10.5.1.27 RPC_OUT_DATA /rpc/rpcproxy.dll beserver.mail.com:6002 80 - 70.21.123.227 MSRPC 401 2 64 Any help would be appreciated. Thanks! Mike