Wednesday , June 10 2020

Moving Mailboxes from Child domain to root domain.

In my Scenario _

Root Domain –

Child Domain –

Customer wants to get rid of and its Exchange servers. So that he move forward to migrate to the cloud. Without involving

Let’s move (Child Domain)

to (Root Domain)



Member of

  • Distribution Group and a Security Group
  • Mailbox Active on iPhone



As Child Domain and Root Domain are in the same Exchange Forest. (They can see and Connect each other without any issues)

New local Move Request to from Child domain To

Once Mailbox is moved. User will go disconnected in Outlook.

Now Consider Mailbox is Moved from Child domain to root domain

Now go to Adsiedit.msc Default Domain Partition of Child domain. Delete any Active Sync Devices below user Object.

or you can use Exchange management shell to remove active sync device of the user.


Now Once All Devices deleted . Now ADMT knows it doesn’t have any leaf object.

Now install ADMT 3.2 on a Server which as access to Child Domain and Root domain.

Now Right Click and Click on User Account Migration Wizard.

image Source Domain

A.Com Child Domain


Select Users from domain.


Choose User Accounts from the Source domain.


Choose OU



  • Update User rights.
  • Migrate Associated User groups

When you migrate Associate user groups. It moves Distribution group and security group objects from child domain to root domain

and if you open the distribution group and security group members . you can see the migrated users are from root domain and child domain are listed.

but the objects is migrated


Do not migrate source object if a conflict is detected in the target domain.




Groups Associated with the user got migrated.


  • Tried some test emails from Source and Destination domain.
  • Distribution list works without any issues.
  • New Configured Outlook Profile where autodiscover of the source domain is pointing to the destination Exchange server. As they have different DNS zones between child domain and root domain.


Once all mailboxes and user objects are moved from child domain to root domain.

We can remove child domain exchange server and Domain controllers without any issues.

About Satheshwaran Manoharan

Satheshwaran Manoharan is an Microsoft Office Server and Services MVP , Publisher of Specialized in Office365 / Microsoft Exchange / Virtualization , Sathesh is an Messaging Expert supporting/Designing/Deploying many medium size businesses to large enterprises when it comes to Corporate messaging and Virtualization Infrastructure

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