Outlook 2010 lost connection to Exchange 2010


  • Running Outlook 2010 on Windows7 laptop in cached mode with RPC over HTTP connecting to Exchange2010. 

    Tried to open Oultook at one of my remote offices and couldn't get a connection.  Came back to the office and could get Outlook online. 

    I've deleted all Outlook Profiles and recreated a dozen times, deleted OSTs, uninstalled Oultook and reinstalled.  Now, I can't get a connection to the server at all.  I tried several mailboxes.  I get queried for authentication, but all I get is: "Cannot open your default e-mail folders. Microsoft Exchange is not available. Either there are network problems ot the Exchange server is down for maintenance."

    I've looked all over the web, and can't find a solution.  Any suggestions would be greatly appreciated!!

    Friday, February 03, 2012 8:57 PM

All replies

  • hi,

    Try the testexchangeconnectivity.com for RPC over HTTP and see what's happending.


    Friday, February 03, 2012 9:41 PM
  • Tests successfully.  The servers seem to be working OK.  I think it's client related.  I can't get a connection on my network.  Oh, and here's something new... If I use my admin ID/PW when prompted for credentials, the profile can open my mailbox.

    I am able to access my mailbox from Outlook 2003 clients on other PCs.

    Friday, February 03, 2012 9:56 PM
  • Hi,


    Verify the configuration of Outlook is correct.

    Verify if the default user change others, but still use old user data file as the default data file.

    If it is normal. Please refer to the following article repair .pst/.ost file



    Wendy Liu - MSFT
    Monday, February 06, 2012 11:58 AM
  • At this time, I'm not even using OST/PST.  I'm just trying to open Outlook with a direct connection.  I can open my mailbox if I use my Admin ID/PW, but not my ID/PW.
    Monday, February 06, 2012 4:00 PM
  • Looked at both links...

    No luck!

    It's definately an authentication issue.  Windows7, Outlook2010, Exchange2010, Windows2003 Directory.  I can log in with my Admin ID/PW, but not my ID/PW.  Both IDs have the same permissions in the directory.  Maybe something is cached in Windows7?? 

    Monday, February 06, 2012 4:02 PM


    Do you have migrated mailbox ? Or use Outlook 2010 connect to Exchange 2003 ?

    By default, Outlook 2003 is disable encryption, but Outlook 2010 is enable encryption.

    So you can try to disable encryption on your Outlook 2010 client.

    And you can also refer to the following link.

    Outlook connection issues with Exchange 2010 mailboxes because of the RPC encryption requirement


    Wendy Liu

    Tuesday, February 07, 2012 2:11 AM
  • I've played with the encryption.  No Help.  It's got to be something with my ID.  I can open the profile using my admin ID/PW.  Nothing has happened my ID though.  Is there a file/files, other than OST/PST, that caches ID information for Outlook 2010 in Windows7? Something else that can corrupt?

    Wednesday, February 08, 2012 7:36 PM


    Please try to open mailbox use your ID on OWA, or open mailbox use MFCMAPI. Verify if it can open your mailbox.

    And have you changed on the account recently ?

    Have you migrated on your Exchange Server ?

    The admin ID can open admin’s mailbox? Or your mailbox?

    Have you delegated on your admin account or your account ?


    Thursday, February 09, 2012 2:23 AM
  • Deleted cached credentials for your account from Credential Manager in Windows 7 Control Panel.
    • Proposed as answer by MWRY Friday, April 13, 2012 1:09 PM
    Friday, April 13, 2012 1:09 PM