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Newbie Connectivity Question - OWA/EWS vs. Outlook Thick Client

    Question

  • Background: We're running into issues where Outlook thick clients (2013 for the most part) have issues connecting to CAS servers and getting access to their mailboxes.  The same accounts continue to work fine via Mac's Outlook client (which I believe uses OWA) as well as via ActiveSync.

    MS is pointing at the "store" process (presumably a worker process associated with an individual database) on our Exchange 2013 farm, and I'm just trying to validate if it makes sense that the communication path the Outlook clients take from client to CAS to MB DB differs from that of the OWA/AS clients even if the mailbox in question resides on the same database.

    Hope that makes sense.  Would love it if someone could point me to a nice overview of protocol flows for Exchange 2013.  I haven't found quite the right combo of search terms...

    Thanks!

    Wednesday, February 17, 2016 6:03 AM

Answers

  • Outlook clients connect using Outlook Anywhere, which could be either RPC over HTTP or the newer MAPI-HTTP.  You can tell more by using Outlook's Connection Status.  That might also give you some clues as to what might be having trouble connecting.

    Outlook for Mac uses Exchange Web Services, not OWA.

    All client access protocols except POP and IMAP (not discussed in your question) use HTTPS.


    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    Celebrating 20 years of providing Exchange peer support!

    Wednesday, February 17, 2016 10:35 PM
    Moderator

All replies

  • Outlook clients connect using Outlook Anywhere, which could be either RPC over HTTP or the newer MAPI-HTTP.  You can tell more by using Outlook's Connection Status.  That might also give you some clues as to what might be having trouble connecting.

    Outlook for Mac uses Exchange Web Services, not OWA.

    All client access protocols except POP and IMAP (not discussed in your question) use HTTPS.


    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    Celebrating 20 years of providing Exchange peer support!

    Wednesday, February 17, 2016 10:35 PM
    Moderator
  • Hi,

    Agree with Ed, you can use outlook connection status to view the type of protocol.

    Please take the following steps, open Outlook - press CTRL key - click on the Outlook icon from right bottom corner taskbar - select connection status.

    You can have a look at the below link to get the Client Protocol Architecture in Exchange 2013

    https://theucguy.net/client-protocol-architecture-in-exchange-2013/

    Please note: Since the website is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

    In addiction, if you have some outlook connectivity issue, I suggest we do an Outlook connectivity test with https://testconnectivity.microsoft.com/  and see what went wrong.

    Regards,

    David


    Thursday, February 18, 2016 6:15 AM
    Moderator