On my initial Lync 2013 project I encountered a problem with the Exchange 2010 UM server not finding a path to the Lync 2013 Edge pool. I was receiving the MSExchange Unified Messaging event 1438, as shown below.
I was able to resolve the issue by running the following PowerShell command on the Exchange UM server (replacing lync-edge.domain.local with your Lync Edge pool’s FQDN):
Get-UmServer | Set-UmServer -SIPAccessService lync-edge.domain.local:5062
Log Name: Application
Source: MSExchange Unified Messaging
Date: 11/14/2012 7:43:00 AM
Event ID: 1438
Task Category: UMCore
Level: Warning
Keywords: Classic
User: N/A
Description:
The UM server has been configured to automatically use the Communications Server Audio/Video Edge resources associated with ‘lync.domain.local:5061’. Inbound and outbound calls involving remote users (located outside the enterprise) might be failing using the current Communications Server Audio/Video Edge resources. To correct the issue, set the SIPAccessService property using the Set-UMServer cmdlet. The Microsoft Exchange Unified Messaging service will start using the Communications Server Audio/Video Edge resources corresponding to the new value.
Did Move-CsExUmContact not work for you (to move the Exchange UM contact object to the new pool)?