Process %1: %2 failed. Caller SIDs: %3. The exception returned is %4. Make sure that the Active Directory site/forest that ...

Process %1: %2 failed. Caller SIDs: %3. The exception returned is %4. Make sure that the Active Directory site/forest that contain the user's mailbox has at least one local Exchange 2010 server running the Availability service. Turn up logging for the Availability service and test basic network connectivity.