Hi allI am new to the parent/child domain conceptWe have a parent domain (parent.com) and recently created a child domain (child.parent.com)Here is what I am trying to do:There is a child domain administrator which will create and manage his users/mailboxes. All mailboxes will be created under the parent domain (eg. user1@parent.com) and mailboxes will be physically located in the parent EX server.I am able to create user/mailbox using the child domain DC which EX management tool is installed. But when I check from the parent domain EX, I cannot see that mailbox. Also, I cannot open that mailbox from Outlook. It says it cannot locate that mailbox.I know I 've done soemthing wrong in the first place. Anyone can point me out or at least give me some guidlines to start with? Thanks alot. Any feedback is appreciated.Cheers,Celic

Hi, Did you create a recipient update service that points to the child domain? Leif

Thanks Leif. Do I need to do that even no one will be using the child domain as the email address??All users created in the child domain will still have an email like user@parent.com....