How to Perform On-Premises Exchange to Office 365 Migration

With the world moving towards the cloud revolution, many organizations are stuck at the Exchange vs Office 365 decision. For any company, migrating thousands of mailboxes (with loads of data accumulated over the years) from on-premises email setup to a cloud based environment is no cakewalk. There are technical aspects to be dealt with, management aspects, cost frontiers and the need of experts in the area. Losing a little information during the process is just not an option.

With such strict requirements, what is the ideal way to migrate Exchange to Office 365? Or, is there a middle road? Let’s dive a little deeper into the topic and find out ways in which the situation can be tackled smoothly.

How about a Hybrid emailing setup?

A hybrid emailing environment is one that has the ability to work with both Exchange on-premises and Exchange online (Office 365). A migration undertaken as part of such a setup is different from a complete Exchange migration to the cloud. Here, you have the option to move existing mailboxes instead of creating new user mailboxes and importing user information, thus saving effort, time and resources. Moreover, in this process migration batches are used to fulfill the remote mailbox move request.

Thus, provided that you've correctly configured a hybrid deployment between on-premises and Exchange Online organizations, it shouldn’t be that difficult to migrate email to office 365.

Things to know before starting

Before starting with the actual process, here are some things you should find out:

• Estimated completion time (this ideally depends upon the number of mailboxes included in each migration batch)
• The required permissions you should have to complete the task and have them assigned
• As mentioned earlier, you should have configured the deployment between your on-premises and online organizations
• Have Mailbox Replication Proxy Service (MRS Proxy) enabled on your on-premises Exchange 2013 Client Access Server (if using Exchange 2013)

Steps to migrate Exchange to Office 365

Here is the complete step-wise procedure to migrate mailbox to Office 365:

Step 1: Create migration endpoints

This should be the first step before on-boarding and off-boarding remote move migrations in an Exchange hybrid environment. These endpoints create the required connection settings for the process.

Step 2: Enable the MRS Proxy Service

If you're using Exchange 2013, enable the Mailbox Replication Proxy Service (MRS Proxy). For this:

• Open the Exchange Admin Center (EAC) and navigate to Servers -> Virtual Directories
• Select the Client Access server, and then select the EWS virtual directory
• Click the Edit icon.
• Select the 'MRS Proxy enabled' check box, and then click 'Save'

Step 3: Migrate mailbox to Office 365 using EAC

In the EAC on the Office 365 node, the 'Remote Move Migration Wizard' can be used to move existing on-premises user mailboxes to Exchange online. For this:

• Launch EAC. In the Office 365 tab click on Recipients -> Migration.
• Click Add +
• Select Migrate to Exchange Online
• On 'Select a migration type' page click Remote move migration -> Next
• on 'Select the users' page click Add + and select the mailboxes to be moved to Office 365
• Click Add -> Ok -> Next
• On 'Enter the Windows user account credential' page, in the ‘On-premises administrator name’ field, enter the on-premises administrator account name.
• In the 'On-premises administrator password' field, enter the on-premises administrator account password
•  Click Next
• You'll receive an endpoint confirmation prompt. If you've created more than one endpoint, choose an endpoint from the drop-down menu.
• Verify that the FDQN of your on-premises Exchange server is listed when the wizard confirms the migration endpoint
• Click Next
• on 'Move Configuration' page, in the 'New Migration Batch Name' field, enter a name for the migration batch.
• Select the 'Target delivery domain for the mailboxes that are migrating to Office 365'. In most hybrid deployments, this is the primary SMTP domain used for the Exchange Online organization mailboxes
• Click Next
• On 'Start the batch' page, select 1 recipient at least to receive the batch completion report 
• Verify that the 'Automatically start the batch' option is selected.
• Select the 'Automatically complete the migration batch' check box. Click New.
• Once the process completes, click 'Finish'
• Now you'll be back at the Office 365 node of the EAC. Here, click on 'Move Request'. This will create a new move request. Right-click on each of the moved mailboxes and select 'Properties'. Here you can verify all general details about the move procedure.

Step 4: Remove completed migration batches

After the move task completes, remove the completed migration batches. For this:

• Open the EAC and navigate to Office 365 -> Recipients -> Migrations
• Click a completed migration batch, and then click on the 'Delete' icon.
• On  the confirmation dialog, click 'Yes'.

Step 5: Re-enable offline access for Outlook on the Web

To migrate mailbox to Office 365 users have to reset the offline access setting in their browser to use Outlook on the web offline. This lets users access their mailboxes even when they’re not connected to a network.

Wrapping it up

That is the entire step-wise procedure for Exchange to Office 365 migration. But this process is rather lengthy, difficult to understand and it might take a lot of time. A recommended, easier, faster and smoother way to complete the migration is by converting on-premises Exchange database file (EDB) to PST format and then directly importing the converted PST into Office 365. For this, we recommend using third-party competent EDB to PST converter Stellar EDB to PST Converter.

This powerful tool efficiently converts all objects within EDB mailboxes to PST format and also enables exporting converted mailboxes to Office 365 as well as Live Exchange Server. Its wide compatibility with different Exchange Server versions and ease of use make this application the most preferred way to migrate email to Office 365.