Hello Group,My problem is I cannot setup up any mailboxes for user@childdomain.parentdomain.com! I have 1 domain controller forest with one parent and some children. I have implemented Microsoft Exchange 2007 on the parent (root) domain controller, but want to allow the child domain controller users to access it. I've setup Ex. 2007 and here is where I am at: 1.) Good news - my person@parentdomain.com is sending AND receiving emails fine to internet. My MX records / configuration are complete -2.) I am using a hubtransport installed on a parent domain and an Edge transport (MX) on parent domain.3.) I have a parent domain and child domain, each with DC's / DNS replicating properly to each other (using replmon) Dns is working perfectly. Everybody can resolve everyone fine in both child and parent.4.) Domain levels are raised @ Windows 2003, these were fresh Win2k3 Server installs.Problem is Exch 2007 removed RUS, which was formerly necessary to implement child domain user access to a parent domain Exchange Server, - so I can't figure out how to get my child domain users into my parent Exchange 2007 ! ! 5.) I have created an Accepted Domain for the childomain.rootdomain.com on my Hub Transport Server.6.) On my Exchange Server 2007 installed on my parent domain, I go to my Ex. Management Console. I navigate to the Server config portion on the left. When I try to create an email address policy, the good news is that the child domain is available as a drop-down selection in the SMTP-Email adress config. Essentially - the Hub Transport Email Address email address policy config portion lets me pick (as a a drop down)Parent domain.comMychilddomain.parentdomain.com This is a good sign! However, strangely enough !! ---- 7.) Problem is, I still can't add a mailbox for anyperson@childdomain.rootdomain.com!! If I go down to the recipient config, mailbox, then create a new mailbox, and then I go to browse the OU, I cannot add any user whatsoever from childdomain.parentdomain.cpmIn fact, if I browse the OU it only shows the parentdomain object Users. I cannot drill down into child domain objects the way I could if I went to the parent domain AD MMC areas- and see them there in the child domain...I can create a user, but they default to one selection ONLY for the email choice. user@parentdomain.com. Now what I need! What am I doing wrong? I know I don't need to install a second Exchange Server in the child domain too. The DNS in the child domain points to the MX which works fine for the parent domain. Any help, please, a little exasperating .... very frustrating ... Thanks! Kahele

Did you Prep that Child Domain?

http://technet.microsoft.com/en-us/library/3c416337-d487-4605-827e-68279ce44fcf.aspxNote: In Microsoft Exchange 2000 Server and Exchange Server 2003, you performed the Active Directory preparation steps by running setup /forestprep and setup /domainprep. Exchange 2007 does not have the /forestprep and /domainprep options.

http://technet.microsoft.com/en-us/library/bb125224.aspx

figured it outturned out to be, under recipient config area in hub transport exchange management consoleRight click, modify recipient scope, select entire forest !

I was having the same issue and while researching I came up with a much simpler solution. Open your E2K7 management console and right click on "Recipient Configuration" and select Modify Recipient Scope. On the next window select "View all recipients in the forest". This will allow you browse your Child domains while creating mailboxes for either existing or new users. Another note, in order for OWA to work for your child domain users, make sure you run setup.com /preparedomain on your child domains. Hope this helps if you haven't fixed it yet.

one additionalif the child domain is windows 2008 R2, you have to running "setup.com /pad" or "setup.com /PrepareAllDomains" in your exchange 2007 sp2 setup.com