One day, on one of my Exchange servers, Users are not getting their E-mail Address field populated. Here are the detail event logs.

Event ID: 9186

Event log: MSExchange SA, Microsoft Exchange System Attendant has detected that local computer is not a member of group ‘cn=Exchange Domain Servers,cn=Users,dc=..,dc=com’. System attendant is going to add the local computer into the group.

Event ID: 9187

Event log: MSExchange SA, Microsoft Exchange System Attendant failed to add the local computer as a member of the DS group object ‘cn=Exchange Domain Servers,cn=Users,dc=..,dc=com’. Please stop all the Microsoft Exchange services, add the local computer into the group manually and restart all services.

How I Fixed it: I simply remove and re-added the Exchange server to “Exchange Domain Servers” group. I also configured the Exchange server to use a different domain