Thanks for your suggestion Simon_Wu; however, it did not work. This is really frustrating. I have researched so much, but I cannot find an answer. Is it an authentication issue? Is it a DNS issue? I cannot figure it out. I am able to ping the server by name and IP, so it must be something with Exchange. Below is the message I get. As a side note, I am performing a manual configuration, not an autodiscover. As far as I understand Exchange 2003 does not have this ability. The computer has Windows 7 64 bit and Office 32 bit. Would a Microsoft Exchange guy please help!!!!!! Please help!!!!

1) You need to check the configuration of Outlook, 2) It might be possible that there is DNS issues on the client PC. --Make sure you able to ping the Exchange Server FQDN from Client PC. --Configure the same outlook profile with any other pc and check if the issue is persisit or not Please Letus know the results. Viral Rathod Blog : http://viralr.wordpress.com

Viral Rathod, Thanks for your reply. 1) You need to check the configuration of Outlook, Yes, I already did and compared it to the Outlook 2003 clients. The only difference I see is in the "Security settings", which was set to Kerberos(NTLM). I tried changing them on the Outlook 2010, but it did not make a difference. 2) It might be possible that there is DNS issues on the client PC. It's possible; however, I am able to ping the server by name and by IP.

Hi all, We have an Exchange 2003 server and clients have Outlook 2003, 2007, and we are trying to use 2010. We are experiencing this strange problem where Outlook 2010 cannot connect to the Exchange 2003 server. What is weird is that if we connect the client via VPN, it connects fine. So, if we connect the client on the local area network where the Exchange is, it cannot establish the connection to Exchange. As soon as we establish a VPN connection, the client connects fine. Any help would be greatly appreciated. Thanks in advance.

Hello, Please create a new test mailbox and log in Outlook to see if it works. BTW, does the user use Windows 7/Vista? If so, disable the TCP autotuning feature by running: netsh interface tcp set global autotuning=disabled netsh int tcp set heuristics disabled netsh int tcp set global autotuninglevel=disabled Thanks, Simon

I am having this exact problem as well. I get that exact same error message. I am using Outlook 2010 trying to connect, from home, over a standard cable internet connection to an Exchange 2003 server. The machine is running Win7 x64 and Office 2010 32bit. DNS is dandy on my home network. I also have an HP Touchpad and its native email client connects to the Exchange server without any problems no matter where I am (home, work, coffee shops, the moon...). Entourage 2008 on my Mac at work connects fine, but it is on the same network as the server there. I have seen some people saying to add certain registry values to HKEY_CURRENT_USER/Software/Microsoft/Office/14.0/Outlook/RPC but I do not have an RPC key in the registry in that location. PLEASE HELP!

Hi Ward_CW, Perhaps a little late for my reply! I don't know if you solved this issue, but here is how I solved it. http://social.technet.microsoft.com/Forums/en-US/exchangesvrgeneral/thread/dc45ce86-1ab3-4fb2-870f-ec414bd76663 Hope it helps.