How to Migrate from Exchange Server 2016 to Exchange Server SE?

With the release of Exchange Server Subscription Edition (SE), there is a rush to migrate to this new edition from legacy Exchange Servers and even the Exchange Server 2016 or Exchange Server 2019. The perfect time to take advantage of the migration path is now as the first Cumulative Update (CU) of Exchange Server SE will not support the coexistence. In this article, we will be going through the stepwise process to migrate from Exchange Server 2016 to Exchange Server Subscription Edition (SE). We will also be touching upon the probable issues and challenges you might encounter and the solutions to minimize downtime and speed up the migration process.

Stepwise Process to Migrate from Exchange Server 2016 to Exchange Server SE

With Exchange Server 2016, you can do a Legacy Upgrade, which means you need to setup a coexistence with Exchange Server SE and move the mailboxes. Let’s discuss the steps you need to take for Exchange 2016 to Exchange SE migration.

Step 1: Prepare the Exchange Server Subscription Edition (SE)

For preparing the new host for Exchange Server SE, you must ensure the following:

• The present Exchange Server is fully-updated with the latest Cumulative Updates (CU).
• Active Directory Schema is updated and supported.
• Have a host with Windows Server 2019 or later and install the Exchange Server Subscription Edition (SE).
• Have a copy of all the certificates, if these are wildcard or specifics.
• Have the documentation updated to the latest changes, including:
  • Relaying configuration.
  • Receive and Send connectors.
  • Routing and other configurations.

You must note that the coexistence of Exchange Server 2016 and Exchange Server SE is temporary. With the first Exchange Server SE Cumulative Update (CU), coexistence will not be possible.

Step 2: Installation of the Exchange Server Subscription Edition (SE)

You need to have a server which has Windows Server 2019 or later joined to the same domain as the Exchange Server 2016 with the recommended requirements of storage and compute, suggested by Microsoft and your selected vendor.

After the installation is complete, before doing anything, you should ensure the following:

• Creation of all the databases needed.
• Installation of the keys and activation.
• Configuration of the domains.
• Installation of the certificates.
• Creation of Send and Receive connectors as the current Exchange Server.
• Confirm all the services, such as Autodiscover, Outlook Anywhere, etc., are working.

Step 3: Migrate the Mailboxes

At this point, you have both the Exchange Servers in coexistence and ready with all the configurations. Now, what you have to do is create a mailbox (as a test) on the new Exchange Server and connect with Microsoft Outlook. This will assist to verify the email delivery and access before start moving the live Exchange Server data.

Once done, you can use the PowerShell command - New-MoveRequest to move the mailboxes from your Exchange Server 2016 to the new server. Here is an example of the command.

This will start the migration of user from the source database to the target database mentioned. The batch name is an optional label to easily track batches, while the priority can be either Low, Normal or High, depending on the criticality of the users.

Here are some options you can use with this command.

To include the archive mailbox, you should add the below parameter:

For scheduled cutover and for coordination of moves, you can use the below parameter:

This will pause the migration of the mailbox between 95% and 99%, until the final cutover is done manually.

In case you would need to resume and finalize the move, execute the below command.

To monitor the progress, you can use the Get-MoveRequestStatistics command as given below.

To get the status of move request with the Suspend parameter, you can use the below command:

If all goes well, you can run the command to move multiple mailboxes in a batch at once.

First, prepare the CSV file with the below syntax with comma separated.

Then, use the below command to run the migration batch.

Step 4: Migrate Public Folders

The steps to migrate public folders are a little different. You need to first create public folders in the new Exchange Server. To do so, execute the command as given below.

Then, get the public folder statistics by running the below command.

Now, you need to create the mailbox mapping file using the below format.

After this, initiate the move by using the below command:

You can use the below command to get the status.

Once done, you would need to complete the move using the Complete-MigrationBatch command.

Step 5: Post-Migration Practices

After all the mailboxes and public folders have been moved, you should follow the practices mentioned below:

• Monitor the mail flow and email delivery.
• Make sure that the perimeter firewalls are routing to the new server.
• Documentation is updated.
• Backups are in place.
• The Exchange Server is properly decommissioned.

Challenges and Alternatives

You may encounter a lot of issues during the migration, such as mailbox move request is pending, mailboxes are in suspend state, issues with large mailboxes or archives, public folder quotas, and misconfiguration of the Exchange Server.

Moreover, there is a chance of human error when it comes to the scripting part. Another thing to note is that the above process doesn’t support the cross-domain and cross-forest migrations.

For overcoming the challenges with manual process, you can take the assistance of Stellar Migrator for Exchange –  a specialized Exchange migration tool. This tool will allow you to easily connect to the live Exchange Server and granularly migrate user mailboxes, shared mailboxes, user archives, and public folders with ease to a newer Exchange Server. It can also supports Exchange Server to Office 365 migration, Office 365 to Office 365 migration, and even Office 365 to Exchange Server migration. Stellar Migrator for Exchange also allows cross domain/forest migrations with ease.

Conclusion

There are many new things that come with the new instalment of the Exchange Server, i.e., the Subscription Edition. Microsoft has given some space on how you can take advantage of this time to move to the new Exchange Server in a smooth way. Till now, the Exchange Server Subscription Edition (SE) is just an Exchange Server 2019. So, migrating to it is smooth and less risky for businesses. Downtime and long/problematic migrations can cost a lot to a business and brand. Thus, it critical to have the right tools for the success of migration project. One tool that you can rely upon for migrating the data from one Exchange Server to another with complete integrity is Stellar Migrator for Exchange.