Hi, I manage a Exchange 2003 Organization where in all Exchange 2003 servers are running on Windows 2003 OS. AD is onWindows 2000 & has a root domain & multiple child domains. All Exchange servers are installed in Domain-A. The Exchange servers host mailboxes for both Domain-A & Domain-B users. Now the requirement is to decommission Domain-B by migrating all users / mailboxes to Domain-A. Please let me know the procedure for the same & also please shareif there are any best practices or practical experiences of this type. Thanks in advance!!

Buddi, This is not quite as simple as you might think. The first thing you need to do is to get the user account moved from Domain-B to Domain-A. Unfortunately, you just can't 'drag and drop'. You need to get the Active Directory Migration Tool (ADMT) to do this. You should use either the v3.0 tool or if the features of the v3.1 sound good. http://www.ditii.com/2008/04/23/active-directory-migration-tool-admt-31-beta/ http://www.microsoft.com/downloads/details.aspx?FamilyID=6f86937b-533a-466d-a8e8-aff85ad3d212&displaylang=en http://bink.nu/news/active-directory-migration-tool-version-3-1-admt-v3-1.aspx This should get you started. Here is a good discussion, also. http://www.eggheadcafe.com/software/aspnet/29421239/move-users-from-one-domai.aspx Jim

As mentioned earlier, my Exchange 2003 servers are already on Domain-A. It has mailboxes of users in Domain-A & Domain-B. Now I have to migrate users from Domain-B to Domain-A. If I migrate user accountsusing ADMT V3, from Domain-B to Domain-A, will they still be able to access emails, since the exchange server is already in domain-A ? Do I need to take any additional steps while migrating ?

Clarify: Your mailboxes for both domain A and domain B stay in the domain A, now you want to migrate domain Bs user accounts to domain A, right? I spent a few hours to test it in my virtual machine, set domain A as root domain, domain B as child domain. I create test account in domain B, test accounts mailbox in domain A. And yes, based on my testing, mailbox can still be accessed after migrating to domain A by using ADMT [Testing environment: Windows server 2003 + Exchange 2003 + Outlook 2003]

Excellent!! Thanks a lot!!!

Glad it help

Could you please give more technicaldetails that this is a safe movement? I mean to say: "after testing it works" is not enough to make this change in a production environment.