Seamless Hybrid Migration from Exchange Server to Office 365

A hybrid migration refers to a deployment strategy that involves connecting an on-premises Exchange Server environment with Exchange Online (Office 365). This arrangement enables the two distinct environments – on-premises and the cloud to coexist and work as a single organization under a common domain name.

The hybrid environment is suitable for big corporate houses that need a steady-paced transition from Exchange to Office 365 with unified mail migration and persistent directory synchronization. This blog describes the method for hybrid migration in detail. It will also discuss the role of an Exchange migrator in carrying out hybrid migration from Exchange server to Office 365.

What is the need for hybrid migration?

Hybrid migration sets the admins free from creating new mailboxes to import information. Here are more factors that contribute to the need for enterprises to migrate from On-premises mailbox infrastructure to the cloud.

• Reduced management overhead
• Easy manageability
• Minimized capital costs to run the server edition
• Hassle-free process
• Data seeding before migration
• Exchange On-premises to Exchange Online migration and vice versa

What are the prerequisites for hybrid migration?

Admins have to work with precision and diligence to make the migration process seamless for the users. Here are some of the crucial prerequisites they have to follow before starting the real process:

Requisite Permissions 

Before migration, the admin should have proper permissions to initiate the process. These may include:

1. On-Premises Exchange Permissions  

These include permissions for the following:

• Organization management role group membership
• Recipient management role group membership  to manage mailboxes and
• local admin rights on the Exchange server for configuration jobs

2. Microsoft 365 or Exchange Online Permissions

The administrator should have been assigned with:

• Exchange administrator role or
• Global Administrator for the hybrid configuration wizard tasks

3. Active Directory permissions

Necessary for environments that use directory synchronization through Microsoft Entra Connect.

Supported version of the Exchange server 

The Exchange server running the On-premises environment should be a supported version, such as Exchange 2019, 2016, or Subscription Edition (SE). In case of an older version, you will need to upgrade it to a supported version before carrying out a hybrid migration.

MRSProxy  enabled Exchange version

When running an older version, such as Exchange Server 2013 or 2016, you should enable the Mailbox Replication Proxy Service (MRSProxy) on the on-premises Client Access servers.

Verified domain

The email domain you want to perform a hybrid migration must be verified and added to Microsoft 365.

Steps to perform a hybrid migration from Exchange Server to Office 365

The process to migrate Exchange mailboxes from On-Premise to Office 365 or vice versa is simple and easy. Follow the steps below for a successful migration:

Here are the steps to help you carry out the hybrid migration:

Create endpoint

This step requires setting connection for the on-premises Exchange server that hosts the MRS proxy endpoint. It helps in performing remote migrations from on-premises Exchange to Exchange Online and vice versa.

Enable MRSProxy

Manually enable the MRSProxy service for on-premises Exchange, depending on the server as mentioned below:

• Enable Client Access Server in case of Exchange 2010 and 2013
• Enable Mailbox Server in case of Exchange 2016,  2019, and SE

Here are the steps to enable proxy service:

• Open EAC with your admin account
• Navigate to Servers > Virtual Directories
• Select Client Access Server > EWS virtual directory
• Click the Edit and check the checkbox corresponding to MRS Proxy enabled
• Click Save > OK.

Hybrid migration using EAC

You can use the remote migration wizard on the Office 365 tab in the EAC. It helps to move Exchange Online mailboxes to the On-premises organization. Likewise, you can also use it to migrate On-premises user mailboxes to Exchange Online organizations.

On-Premises Mailboxes migration to Office 365

• Open Exchange Admin Center (EAC)
• Navigate to Office 365 > Recipients > Migration > Add
• Click + icon to choose the option, Migrate to Exchange Online
• In the resulting window, select a Migration Type, select Remote move migration
• Click the Next button, and in the next screen, click + sign on Select the user page
• Click Add > On-premise User and then click Add button
• Provide credentials for the On-Premises administrator account under the Enter the Windows user account credential screen
• Click Next to receive endpoints confirmation and check if the confirmation page has listed the FQDN number
• In the move configuration window, provide the migration batch name
• Next, select the Target delivery domain for the mailboxes that are migrating to Office 365.
• Choose Move Primary mailbox along with Archive mailbox, before clicking Next button.
• In the resulting screen, open the Start the Batch option and select the recipient
• Select Automatically Start the batch > Select automatically complete the migration batch checkbox > new

Office 365 mailboxes migration to the on-premises environment

You may also move Office 365 to On-Premises Exchange by following the steps below:

• Open EAC > Office 365
• Click Recipients > Migration
• Click Add, and in the options that surface, choose Migrate from Exchange Online
• Choose Select the users that you want to move from Select the User window
• Click + sign to choose the Exchange Online users you wish to move to the on-premises organization
• Click Next to see the Confirm the migration endpoint window
• Check the listing to ensure the listing of the FQDN of your on-premises Exchange server
• Click Next > Move Configuration window
• In the New migration batch name text field, type the name of your migration batch
• Provide the target delivery domain under the Target delivery domain for the mailboxes option
• Switch to Start the batch page
• Select one recipient to get the batch complete report
• Select Automatically start the batch option
• Click the checkbox corresponding to Automatically complete the migration batch
  

Remove migration batches

After the completion of hybrid migration, remove the migration batches. This will minimize the possibilities of errors in situations that require moving the same users again. Here are the steps:

• Open EAC
• Navigate to Office 365 > Recipients
• Under Migration, click Completed Migration Batch option.
• Click Delete option and then, click Yes to confirm the deletion

Re-enable OWA to resume offline access

Once the migration is complete, enable offline access to the Outlook Web App (OWA) for easy access to mailboxes, even when offline. Specifically, after the migration from Exchange to Office 365 is over, reset the offline access setting to use Outlook on the web when not connected to a network.

Verify the working of the process

This will check if the hybrid migration you just performed is working fine.

• Open EAC > Office 365
• Click Recipients > Migration
• Look for the mailboxes selected in the wizard having move status
• Ensure that the Status value is syncing during the mailbox migration
• Successful movement of mailboxes to On-Premises or Office 365 will complete the hybrid migration

Limitations of manual Hybrid Migration

This method moves mailboxes to Office 365, but it is a cumbersome process and requires the intervention of technically skilled admins to configure a healthy hybrid system. To avoid these hassles, you can do hybrid migration from Exchange server to Office 365 through an Exchange migrator tool.

Exchange migrator tool for seamless hybrid migration

When manual methods appear hectic and time-consuming, advanced migration tools can help you perform the task with ease and precision. Here are the advantages of adopting any of these automated tools:

• Support for cross-forest, same-domain, and cross-domain migration
• Support for cut-over, staged, and hybrid migration
• Exchange On-Premises to Exchange Online (Office 365) and vice versa migration
• Office 365 Tenant-to-Tenant Migration
• Exchange to Exchange Migration
• Concurrent migration to move multiple mailboxes and their items together
• Auto-mailbox matching to map mailboxes on the source and the target server by using the mailbox ID

When searching online for an ideal tool that provides all these features, you will find Stellar Migrator for Exchange as a viable option. It can perform seamless and quick migration of mailboxes, public folders, and archive mailboxes. Specifically, for large-scale migrations, it is an ideal Exchange migration tool.

It supports seamless migration of mailboxes, public folders, and archive mailboxes with minimal downtime. The software ensures data integrity and provides detailed reports for complete transparency. Its intuitive interface makes it ideal for Exchange admins handling large-scale migrations.

Conclusion

Hybrid migration is a widely used method to move mailboxes from Exchange to Office 365 environment. Admins perform this job to enhance management overhead, data seeding, and ensure easy manageability, among other benefits. To perform it, you should have the required permissions, a supported Exchange server version, MRSProxy enabled, and a verified domain.

You can do an On-Premises Mailboxes migration to Office 365, as well as Office 365 mailboxes migration to on-premises environment. However, the steps to perform the migration are a bit complicated and need in-depth technical expertise.

To avoid such problems, admins use Exchange migrator tools, such as Stellar Migrator for Exchange. These tools facilitate quick and successful hybrid migration from Exchange server to Office 365 and vice versa without hassles.