Hi, I've manage to setup Exchange 2003 Server SP2 without any Front-end. I have another 2 seperate domain controllers with both configure as Global Catalog at the same LAN. So here's the scenario, to configure Exchange 2003 Server SP2 using RPC over HTTPS without Front-end, I've actually refer to this guide at Microsoft: http://technet.microsoft.com/en-us/library/aa997232.aspxbut still unable to get it running. To put in short, I've check through all the configuration below but still unable to get RPC over HTTPS running, via the internal network and through the Internet as well: 1. RPC proxy service installed and started 2. The RPC Virtual Directory at IIS, Allow Anonymous check box has been cleared, the required SSL and 128-bit encryption has also been checked. 3. Modfiy the registry for rpcproxy: servername:6001-6002; server.domain.local:6001-6002; servername:6004; server.domain.local:6004; 4. Added an entry at the NTDS registry at both domain controllers: ncan_http:6004 5. The certificate that was generate is also trusted and valid (using self-signed Microsoft CA server within the LAN), to confirm this, I've actually installed the certificate at a laptop and access OWA, IE didn't prompt me any warning page as the certificate has already been installed to the machine. 6. On the client level, the external domain name was matching with the certificate 7. At my client, I've change the host file by pointing the external domain name to the Exchange internal IP 8. After executing the outlook /rpcdiag for the Outlook profile, the connection would take a while before it switches to TCP/IP 9. When connecting from the Internet (the IP and hostname in the host file has been removed), the Outlook indicates "Connecting" to the Exchange Servername and "--" under the referral to the Domain Controller. After a while, the status shows disconnected. I've also tried telnet to the specific ports (6001,6002, 6004) above and got the screen at command which looks something like this ifI can recall correctly: ncan_http 1.1. I've also used the rpc troubleshooting tools from the Windows Server 2003 resource kit but still can't find any solution out of it as the results was all positive that the RPC services are running fine! Could someone please help me on this as I've been stuck for the last 2 months! Regards, James Ooi

Add the ports 100-5000 to the rpcproxy registry key. Regards, Jos