|Component:||Microsoft Exchange Directory Access Service|
|Message:||Process <process name> (PID=<process id>). All Domain Controller Servers in use are not responding:<fully qualified domain name>|
This event indicates that the DSAccess component on the Exchange server was unable to find any domain controllers suitable for Lightweight Directory Access Protocol (LDAP) queries. This can result in the halting of mail flow, so it should be investigated immediately.