Please send any and all suggestions. We are attempting to add an additional Exchange 5.5 to an existing Exchange 5.5 Organization and Site. During install we are able to join the existing site and the information appears to be correct. However during final phase of the install on the new server we always receive an error that directory replication was not successfull. Stop and restart Directory Services and try the install again. Both servers have NT 4.0 SP6a, the existing Exchange 5.5 server has sp4. Please help.........extremely ignorant and frustrated!! Thanks so much in advanced!