I manage an Exchange 2007 infrastructure in a forest root domain (contoso.com). We have a child domain (child.contoso.com) with an exchange 2003 infrastructure. The child domain does not want to run Exchange any more. Does anybody know if it is supported to have child domain users in the forest root domains Exchange infrastructure? I know it works it technically works, but I am concerned when it comes to removing the child Exchange 2003 infrastructure.

Hi, There should be no problems in having child domain user mailboxes located in the root domain. Just prepare the child domain (exchange 2007 setup /preparedomain) and move the mailboxes to the root domain. Leif