Exchange OWA IM integration and Lync trusted application pools

I am a bit ashamed to say that I wasted most of a day on this, but I’m posting this in the hopes that I can help someone else avoid the same mistake I made.

I just spent about five hours troubleshooting why I couldn’t get Exchange 2013 Outlook Web App to display IM and presence data from a Lync 2013 standard edition server. I had carefully followed the integration steps in the documentation, including the part that says this:

If you have installed the Microsoft Exchange Unified Messaging Call Router service and the Microsoft Exchange Unified Messaging service on the same computer then there is no need to create a trusted application pool for Outlook Web App. (This assumes that the server in question is hosting a SipName UM dial plan.

So, having read that, I didn’t set up a trusted application pool or trusted application… and IM didn’t work.

I fussed with certificates. I read a ton of documentation. I swore. I drank too much diet Coke. I ran OCSLogger and found errors about an unknown peer. “AHA!” I thought. “There must be an error in the docs and you really do need to create a trusted application pool.”

So I created the pool and the trusted app. Two quick lines of PowerShell, a quick login to OWA, and voila:


As much as I would like to claim that it was a documentation error, this was pure fail on my part: the problem was that my Exchange 2013 server doesn’t host a SIP dial plan, so Lync doesn’t automatically add it to the Lync known servers table. It will have a SIP dial plan when I get to the next section of this chapter, but that’s a post for another day.

So, in summary: yes, you do need to create a trusted application pool and application for your Exchange servers even if they are multi-role unless they are hosting a SIP dial plan. 

Now, time for another diet Coke…


Filed under FAIL, UC&C

5 responses to “Exchange OWA IM integration and Lync trusted application pools

  1. Juan

    They’ve really made this complicated. I spent days troubleshooting this in an environment with load balanced cas/mailbox (hub) servers and single role mailbox servers in a DAG, with Exchange UM and an enterprise Lync 2013 pool. In this case I was hosting a SIP dialplan, but the UM/UMCR servers were separated. The combined CAS/MB servers made it confusing as to where the web.config needed to be updated, or if the app pools were needed in Lync..I hope CU2 addresses some of this.

  2. Rian Strydom

    HI There,

    It seems i have exactly the same problem as you had. Would you mind sharing the steps you followed to create the Trusted app and pool please?

    It would be much appreciated.

    Kind Regards

  3. Loom

    Thanks for your post 🙂 I was having the same issue, and simply applying the two powershell commands did the trick ! Thanks

    • Cesar

      I was wondering what the two powershell commands were to make this work.



      • Cesar

        Ok, i just found the issue and it was in the web config file. example below

        I made a mistake and put in the lync pool FQDN in the IMServerName area and it should have been the LyncFE server name instead. I swapped it out and all is good to go now!



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