I have server 1 and server4 as domain controllers. I confirmed this becuase under AD Users and Computers, these two server are listed in the domain controllers OU. However, under AD Sites and Services, I see server3 which is not a domain controller. Server3 is my exchange server. My question, can I delete this object (server3) in my AD under sites and services since it's not a domain controller? this might explain why in my server1 event log under directory service, I'm getting a event code 1864 NTDS replication error. Just need confirmation.