Outlook 2016 with Exchange 2016 authentication popups RRS feed

  • Question

  • After fixing a SPN issue we were good with Outlook 2010 and 2016 with Exchange 2016, however when we installed CU4 anyone that was moved to Exchange 2016 and was running Outlook 2016 is getting a authentication prompt when in cached mode.

    Outlook 2010 users have no problem (and can access the public folders that are still on 2010 servers). Mapi/HTTP has been enabled at the Org level so I found the registry key that forces Outlook to use RPC/HTTP. Had 3 users install it and reboot, after that no more prompts.

    So the question is now why/where are those prompts coming from? Anyone have any thoughts/ideas.

    We tried to troubleshoot with Fiddler, but interestingly once fiddler is running we don't see the extra prompts. It's like it's passing credentials correctly for Outlook and fixes the issue.
    Friday, February 10, 2017 8:25 PM

All replies

  • Hello,

    Is your Namespace's configuration ok ?

    You can verify using these PS commands. Also pay attention to your internal URLs :

    Get-OutlookAnywhere | Select Server,InternalHostName,ExternalHostName
    Get-OWAVirtualDirectory | Select Server,InternalURL,ExternalURL
    Get-ECPVirtualDirectory | Select Server,InternalURL,ExternalURL
    Get-OABVirtualDirectory | Select Server,InternalURL,ExternalURL
    Get-WebServicesVirtualDirectory | Select Server,InternalURL,ExternalURL
    Get-MAPIVirtualDirectory | Select Server,InternalURL,ExternalURL
    Get-ActiveSyncVirtualDirectory | Select Server,InternalURL,ExternalURL
    Get-ClientAccessServer | Select Name,AutoDiscoverServiceInternalUri

    Also, if you have Split Brain DNS configured, make sure that your entries poitns to the right servers.

    Are you behind a TMG or an ISA Server ?

    Best Regards,

    Gilles Tremblay
    MCSE Server | Desktop | Messaging | Collaboration | Productivity | Mobility | Cloud Platform and Infrastructure

    Dont forget to mark as Answered if you found this post helpful.

    DISCLAIMER: This post is provided "AS IS" with no warranties of any kind, either expressed or implied, and confers no rights. Always test before!

    Friday, February 10, 2017 10:07 PM
  • Hi Richard,

    I think you should try to set MAPI virtual directory to Negotiate authentication. That should help 

    Set-MapiVirtualDirectory -Identity "ContosoMail\mapi (Default Web Site)" -InternalUrl https://contoso.com/mapi -IISAuthenticationMethods NTLM,Negotiate,OAuth

    Saturday, February 11, 2017 2:19 AM
  • Hello Richard,

    Any updates with above suggestion?

    Base on your description, I know that migrated mailbox in Exchange 2016 will get an authentication prompt when configure Outlook with MAPI over HTTP, however works with RPC over HTTP.

    If this issue remain exists, please check:
    1. How about re-create an Outlook profile with problematic mailbox for testing?
    2. Open Connection Status, check each channel and find out which's connecting.

    Meanwhile, help to collect the screenshot for this popup.

    Best Regards,

    Allen Wang

    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    • Proposed as answer by Allen_WangJF Wednesday, February 15, 2017 4:32 PM
    Monday, February 13, 2017 5:53 AM
  • Thanks,

    Ran all the commands and the namespaces all look correct.  We are running a split-brain DNS and all the internal namespaces point to the Load balancer.  Bypassing the loadbalancer with a Host file entry leads to the same behaviour and we've cycled through all 4 of the 2016 servers that way.

    Monday, February 13, 2017 12:53 PM
  • Hello,

    Any updates with Akabe's suggestion to add Negotiate authentication in MAPI VD?
    Also, please give an update with my suggestion to take a screenshot when issue occurs.
    It's helpful for further assistance.

    Best Regards,

    Allen Wang

    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Tuesday, February 14, 2017 6:01 AM