We have a co-exist Exchange 2010 / 2013 environment and we are seeing this in Event logs on our our two CAS only.  These are in production but all data is still in 2010, 2013 just the proxy right now:

Test-ActiveSyncConnectivity 
   -ClientAccessServer "RED-INF-MXCS-P2.esri.com" 
   esri.com/Foglight/fgl_wmi 
       Local-ConsoleHost-Unknown 
   5996 powershell.exe 

The specified Client Access server was not found in Active Directory.   

    + CategoryInfo          : ObjectNotFound: (:) [Test-ActiveSyncConnectivity], LocalizedException
    + FullyQualifiedErrorId : [Server=RED-INF-MXMB-P3,RequestId=a2c66548-3d38-4426-9314-7ff807213875,TimeStamp=5/18/20
   15 9:33:49 PM] [FailureCategory=Cmdlet-LocalizedException] 18DA4E92,Microsoft.Exchange.Monitoring.TestMobileSyncCo
  nnectivity
    + PSComputerName        : red-inf-mxcs-p2.esri.com

• Edited by Mark Schuljak Monday, May 18, 2015 10:04 PM more info

Thank you for the response; but the correct names do show up; part of what makes this so strange to troubleshoot.

Mark Schuljak

RED-INF-MXCS-P1     empty.local/Confi... ClientAc... Enterprise  Version 15.0 (Bu...

Also, when I do try to run Test-ActiveSyncConnectivity ClientAccessServer server name I get the error saying that the server is not a CAS yet it was just listed as a CAS when you run Get-ExchangeServer.  Very frustrating, thanks....

• Edited by Mark Schuljak 15 hours 30 minutes ago more info