The Microsoft Exchange Unified Messaging service on the Mailbox server has been configured to automatically use the Lync ...

The Microsoft Exchange Unified Messaging service on the Mailbox server has been configured to automatically use the Lync Server A/V Edge resources associated with '%1'. Inbound and outbound calls involving remote users (located outside the enterprise) might be failing using the current Lync Server A/V Edge resources. To correct the issue, set the SIPAccessService property using the Set-UMService cmdlet. The Microsoft Exchange Unified Messaging  service will start using the Lync Server A/V Edge resources corresponding to the new value.