CodeTwo Exchange Migration

CodeTwo Exchange Migration tool is one of the great products from CodeTwo, which allows us to migrate Exchange mailboxes from one version of Exchange to the other version of Exchange. It can be a direct migration from Exchange to Exchange or from the SBS to Exchange and can be used in exchange cross-forest scenario as well. It also supports to migrate from non-Microsoft products like Google apps or Gmail to Exchange servers. It is easier and faster to use; and safer to migrate exchange in the below supported scenario.

· Exchange 2003, 2007 to Exchange 2010 migration

· Exchange 2003, 2007 to Exchange 2013 migration

· Exchange 2010 to Exchange 2013 migration

· Google Apps to Exchange migration

I think the most interesting feature is the support for cross-forest migration. Cross-forest migration using traditional tool it more complex, tedious and can be extremely slow and time consuming.

In this article we will perform cross-forest migration using the CodeTwo Exchange Migration tool. Normally, organizations perform cross-forest migration when there is a merger or acquisition, a security reason or when leaving the old environment and when starting a fresh one, etc.

Our lab environment consists of two forest – Source forest and – Target forest, which allow users to migrate from source forest to target forest.


As part of the migration, we need to prepare our environment to perform the cross-forest migration. Given below are the configurations necessary between the two forests which help to perform the smooth migration.

1. Configure DNS resolution between and

2. Configure Trust between the two forests, and

3. Configure the mail flow between source to target using the send and receive connectors

4. At the domain, change the accepted domain as an internal relay to make sure that emails continue to be received even after the migration of mailbox to blue domain.

5. Configure Free busy sharing between and

6. Configure GAL Sync between and

7. Install and Configure ADMT and password export server which will export the password to the target account after user account migration.

8. Migrate users AD account from source to Target forest using ADMT

9. Finally, enable the mailbox for all the migrated users at the target forest. This can be done using PowerShell or using Exchange management console.


We are almost done with the environment configuration. Next, install CodeTwo Exchange Migration tool on any machine on the source forest with the necessary prerequisites:

Given below are the step by step instruction to configure CodeTwo Exchange migration tool and migrate the users to the target forest.

1. Login the machine where Exchange migration tool is installed with the Domain admin account

2. Run “ Exchange Migration Administrator Panel” from the start menu

3. Source server connection wizard helps to connect to the source forest. Select the option “on-Premises” Exchange server and click on Next


4. Select the Exchange 2010 server from the (source) forest and make sure to select the Administrator account which has necessary permission to enumerate mailboxes in the source forest and then click on “Next”


5. Select the necessary folder for migration and by default, most of the folder is selected except the junk folder. Keep the default settings and click on “Next”


6. “Email address rewriting” has to be checked when mailbox has to be migrated to the different forest, it rewrites the email address based on the target forest. Since the new forest has a different domain and its email address is different, these settings are mandatory.


7. Finally, verification checks the source server connection and validates administrator account for the necessary permission and group membership.


8. Target server connection helps to connect to the target forest servers.

9. I would prefer to connect manually using FQDN of the Target exchange 2010 server. Exchange Web service URL (EWS URL) gets auto filled based on the target exchange server name and click on “Next”. EWS URL is necessary to connect and access the mailbox during the migration.


10. Enter the User Principal Name (UPN) and password of the target forest administrator account at the Admin’s credentials, and click on “Next”


11. Final verification allows us to validate the target server connection, impersonation rights to access the migration mailboxes through PowerShell.


With this we are almost ready to start the migration. Identify the source mailbox which you want to migrate and associate it with the new target mailbox in the CodeTwo Exchange Migration Administration panel. Association can be done both manually and automatically. Manually, you can select the source mailbox from the list and then highlight target mailbox in the window. This process is painful, when you have larger number of users to migrate. Automatically, association can be done by selecting all the users and click on Automatch button on the Administration Panel’s ribbon. This automatically matches the all the users account from the source forest to the target forest and generate the report for the reference. Once the association is done, you can start the migration. By default, it can only migrate two mailboxes at a time and this count can be increased by modifying the settings at the administration panel.

I personally feel I like the tool and it helps me to perform migration tasks in a simpler, easier and more effective way than using the traditional migration tool. It has a simple GUI which helps the administrator to perform the operation much easier. Again, it supports various migration scenario and even perform the direct upgrade from Exchange 2003 to Exchange 2013. It voids any kind of caveats which occur during the migration and also avoids the complexity of two step migration. CodeTwo also has a great support team which can help us to address any queries, issue or problem whenever there is a situation

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