Exchange 2013 EWS C# RRS feed

  • Question

  • Environment is mixed Exchange 2007 and Exchange 2013. We are in the process of migrating to Exchange 2013 but have a custom transport agent in 2007 that is not working correctly on the 2013 servers and is, therefore, preventing us from migrating mailboxes.

    I’m using EWS managed API to look for items in the Contacts folder of a mailbox. Everything works when I use credentials of the mailbox user itself, but when I use another mailbox that has read access to the mailbox I’m connecting to I get the below error:

    “Exchange Web Services are not currently available for this mailbox because it could not determine the Client Access Services Server to use for the mailbox."

    For example, if I create new ExchangeService using MailBox1 credentials I can call FindItems on MailBox1 contacts with no issues, but when I use another mailbox called ContactManagerMailBox to do the same it fails although ContactManagerMailBox mailbox is given access to MailBox1.

    In addition to this working well in our current 2007 environment, it also works well in a test Exchange 2013 environment so it's possible that the co-existence has something to do with this not working.


    Monday, April 18, 2016 9:23 PM

All replies

  • Learn about folders and mailbox items and how your EWS Managed API or EWS client represents them:

    Updates for Exchange 2013: https://technet.microsoft.com/en-us/library/jj907309%28v=exchg.150%29.aspx

    Common Support Issues with Transport Agents: https://exchangemaster.wordpress.com/2013/11/18/common-support-issues-with-transport-agents/

    Also check this earlier thread:

    Step-by-Step Guide to Migrate from Exchange Server 2007 to Exchange Server 2013:

    Tuesday, April 19, 2016 12:35 PM
  • Only one of those links mentions this particular error message...

    “Exchange Web Services are not currently available for this mailbox because it could not determine the Client Access Services Server to use for the mailbox."

    And that one is in reference to Public Folders.

    That link is also where we got the idea to test using the actual credentials of the mailbox we were testing against, which did work.
    The question is, how do we make it work without having to enter those credentials, which is not feasible?


    Tuesday, April 19, 2016 5:14 PM
  • I would recommend the use of application impersonation for your EWS solution. I am not sure about the recommendation from Microsoft, but from my experience its the best and most robust way to access multiple mailboxes....



    Businessprocessautomation with the EWS SQL Interface SQLExchangeSync

    Thursday, April 21, 2016 8:29 AM
  • Turned out we had the wrong path for EWS in our config file. This is working now. Thank a lot.


    Thursday, April 21, 2016 7:40 PM