none
Outlook 2010 not connecting to Exchange Server 2003 using SSL (outlook anywhere problem)

    Question

  • I am running Exchange Server 2003.  I have a set of users who have upgraded to Outlook 2010 from Outlook 2003.  After the upgrade Outlook 2010 will no longer connect to the Exchange server using RPC over HTTP.  One of the clients was connecting for a few weeks and then stopped.  All of the clients are installed under Windows 7.  I've verified the certificate is OK and that the Outlook 2010 configuration is correctly specifying the use of RPC over HTTP (with SSL forced and configured correctly).  I can login to the the Exchange server using the Web client and HTTPS with no certificate errors (the certificate is a self signed certificate that has been properly installed on the client machine as trusted).

    When I run "outlook /rpcdiag" I observe repeated connection attempts that fail continuously.

    If I connect using the same Office 2010 client when the client is on the LAN with the exchange server, the client connects successfully using RPC with no issues.

    I can connect remotely from Outlook 2003 clients configured identically, but on the same remote LANs using Outlook 2010 fails as described above.  It is acting as if Outlook 2010 is not attempting to negotiate RPC over HTTP even though it is configured to do so.

    No errrors are being generated in the error logs when Outlook 2010 fails to connect.

    If I establish a VPN (for testing only) from the client to the Exchange LAN, Outlook 2010 will connect using RPC over TCP, but this defeats the purpose of "outlook anywhere" and I don't want all my users to use a VPN.

    (As an aside, I have observed that even with Outlook 2003 configured to use only RPC over HTTP on slow and fast networks, the /rpcdiag option shows that Outlook still tries direct RPC over TCP first before trying over HTTP.)

     

    Friday, May 14, 2010 3:45 PM

Answers

  • I found a fix to this problem.  I recalled that I had a similar problem with Outlook 2007.  This link described a registry edit that fixed the problem for Outlook 2007: http://support.microsoft.com/kb/913843

    I created a similar entry in the registry for Outlook 2010 by adding the following registry entry and it fixed the problem:


    [HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\RPC]
    "DefConnectOpts"=dword:00000000

    Hopefully this will be of help to others.

    Does anyone know where this registry key is documented?

    • Marked as answer by Daledj Saturday, May 15, 2010 2:37 PM
    Friday, May 14, 2010 5:29 PM

All replies

  • I found a fix to this problem.  I recalled that I had a similar problem with Outlook 2007.  This link described a registry edit that fixed the problem for Outlook 2007: http://support.microsoft.com/kb/913843

    I created a similar entry in the registry for Outlook 2010 by adding the following registry entry and it fixed the problem:


    [HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\RPC]
    "DefConnectOpts"=dword:00000000

    Hopefully this will be of help to others.

    Does anyone know where this registry key is documented?

    • Marked as answer by Daledj Saturday, May 15, 2010 2:37 PM
    Friday, May 14, 2010 5:29 PM
  • This solved my problem too. Thanks so much for posting the solution.
    Steve
    Wednesday, November 17, 2010 2:53 AM
  • I am about to roll out Office 2010 to all of my people, however I am concerned with this post.  The majority of my users take advantage of RPC over HTTP in Outlook 2003.  Does this setting automatically set itself?  Am I going to need this regkey for all of my laptops using RPC over HTTP?  If so, should I just add that key to the installation?

     

    In addition, do other settings move over as well?  I am having some difficulty in finding a good list.  I am curious about Outlook shortcuts (in Outlook) and other things like signatures and the like.  Will an archive PST automatically reattach?

    Thanks

    Tuesday, January 03, 2012 6:29 PM
  • This didn't resolve my issue. I am using Windows 7 Enterprise 64bit & Microsoft Outlook 2010. Still cannot connect to the Exchnage Server no matter who logs in or what profile I am using.
    Wednesday, August 01, 2012 1:41 PM
  • Same issue here, the registry suggestion didn't help - I am running Windows 7 Professional 64-bit and Outlook 2010 32-bit. RPC connection fails, Outlook shows in "DCDIAG" mode that it'll time out and eventually connect using TCP/IP.


    Monday, August 06, 2012 6:43 PM
  • Daledj:

    It's documented here: http://support.microsoft.com/kb/913843

    • Edited by Chelseau Thursday, October 04, 2012 1:31 PM meh
    Thursday, October 04, 2012 1:30 PM
  • Is there a "fix it for me" solution for this problem with Outlook 2010, Windows 8 OS, and OWA (Exchange Server 2003)?
    Wednesday, September 04, 2013 9:40 PM