How to Migrate Exchange Mailbox to Office 365? Top 5 Ways

Admin ~ Modified: October 29th, 2022 ~ Microsoft Exchange Server ~ 10 Minutes Reading

Summary: This write-up covers all the migration elements that need to be considered when planning to migrate Exchange mailbox to Office 365 safely. The main motive here is to provide a complete walkaround of multiple ways that may help users and Exchange admins to migrate from Exchange mailbox to Office 365. Keep in touch with this guide as it will be updated regularly in order to reflect the recent developments in Exchange and Office 365.

With time, new cloud technology is emerging to boost development & help share information at work. And, Office 365 is one of the leading cloud techs that millions of users rely on, to carry out their day-to-day business operations. As a matter of fact, these days, many On-premise Exchange users are getting inclined toward Office 365. However, unfortunately, most of them are not aware of how to migrate mailbox from Exchange to Office 365.

So, to help the users, this technical guide will put light on various methods to perform Exchange to Office 365.

But, first, let’s understand the importance of the Office 365 cloud platform and the reasons for choosing it over the On-premise Exchange.

Why is Office 365 Better Option Than On-premise Exchange?

First of all, Exchange servers work on a fixed cycle model. That means Microsoft ends the mainstream support systems and stops updating the security for the Exchange server after a fixed period of time. This is the main reason that users are now considering Office 365 as a better option.

Further, let me ask you a question, what’s so important in business? You all must agree that it is ‘Efficiency’ & ‘Productivity’.Being able to create, collaborate, and communicate seamlessly, makes any organization productive & efficient. And, Office 365 provides that facility for the convenience of the users.

Now, if you talk about the cost of maintenance, then it comes in favor of Office 365. Because, unlike on-prem servers, Office 365 doesn’t require any dedicated staff to keep on upgrading the hardware and software since it is a cloud-based platform.

Another important aspect is security. What do you think, which one must have the better security option? Yes, it’s Office 365! Since it offers two-factor authentication, the chances of unauthorized access to your crucial data are almost negligible.

Moreover, when it comes to the flexibility of accessing the files then the hosted exchange environment limits the accessibility to a building. Whereas, using Office 365, it makes possible for users to work on their files from anywhere and on any device.

And, for these various benefits, organizations are migrating from Exchange mailbox to Office 365.

Now, let’s have a look at the different methods.

How Can You Migrate Exchange Mailbox to Office 365?

There are two options available for you. Either you can use any of the manual methods or an automated method.

The manual methods include;

  1. Cutover Migration
  2. Staged Migration
  3. IMAP Migration
  4. Hybrid Migration

And, 5th method is using the automated tool i.e. the Most Secure Migrator Wizard Exchange Migration Tool.

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Let’s first start with manual methods.

  1. Cut-Over Migration

By using the cutover migration, you can move the contents of user mailboxes from an on-premise server to Office 365 at once.

This migration method supports all the versions i.e. 2003, 2007, 2010, 2013, 2016, & 2019 Exchange servers.

Note- The duration of migration will vary based on the number of mailboxes in a batch, the size of each mailbox, and the network capacity

Step 1: Start preparing for a Cutover migration

  • Add on-premise Exchange as an accepted domain of your Office 365
  • Then, set up Outlook Anywhere on your on-premises Exchange server
  • Next, verify that you are able to connect to your Exchange using Outlook Anywhere by running the following commands.
  • $Credentials = Get-Credential
  • Test-MigrationServerAvailability -ExchangeOutlookAnywhere -Autodiscover -EmailAddress <email address for on-premises administrator> -Credentials $credentials
  • To access the mailboxes in your Exchange organization, assign an on-premise user account the necessary permission.
  • Before migrating, disable UM(Unified Messaging) on the mailboxes.

Step 2: For successful email migration, Office 365 needs to connect and communicate with the source email system.

  • You need to create a migration endpoint.
  • Run the below commands in Exchange Online PowerShell for creating an endpoint:-
  • $Credentials = Get-Credential
  • $TSMA = Test-MigrationServerAvailability -ExchangeOutlookAnywhere -Autodiscover -EmailAddress -Credentials $credentials
  • New-MigrationEndpoint -ExchangeOutlookAnywhere -Name CutoverEndpoint -ConnectionSettings $TSMA.ConnectionSettings
  • Do the verification by executing the below command
  • Get-MigrationEndpoint CutoverEndpoint | Format-List EndpointType,ExchangeServer,UseAutoDiscover,Max*

Step 3: For this, you need to create the migration batch.

You can manually create a migration batch or include the Autostart parameter to create automatically.

Following are the cmdlet:-

  • For manual- New-MigrationBatch -Name CutoverBatch -SourceEndpoint CutoverEndpoint
  • For Automatic– New-MigrationBatch -Name CutoverBatch -SourceEndpoint CutoverEndpoint -AutoStart

Next, verify whether it worked or not by running the below command.

  • Get-MigrationBatch | Format-List

Step 4: Now, start the migration by executing the following command in Exchange Online PowerShell.

  • Start-MigrationBatch -Identity CutoverBatch

Then, run the below command to verify whether the migration process successfully started or not.

  • Get-MigrationBatch -Identity CutoverBatch |  Format-List Status

Step 5: Previously, your MX record was pointing to your source email system. So, you need to route your emails to Office 365 after the completion of the migration process.

Step 6: Once you confirm that all the emails are being successfully migrated. And, If users are notified about the same, then you can delete the cutover migration batch.

To do so, run below command line

  • Remove-MigrationBatch -Identity CutoverBatch

Step 7: Make sure to assign Office 365 user licenses to activate migrated accounts. Otherwise, it will automatically get deactivated after 30 days.

Step 8: Need to perform post-migration tasks

  • Configure an Autodiscover DNS record so that users can easily access their mailboxes.
  • When you ensure that all the emails are there in their destination and you no longer need to maintain your on-premise environment. Then, you can decommission the on-premises Exchange server.
  1. Staged Migration

You can execute the data migration in batches by using this method. But, the only limitation is that your source must be either Exchange 2003 or 2007 version.

Let’s have a look at the migration tasks:

  1. Configure Outlook Anywhere on your On-premise Exchange server, verify the same, and Set & Assign permissions.
  2. Verify that you own the domain using the domains wizard.
  3. Utilize directory synchronization to create users.
  4. Create a master list of mailboxes for the migration.
  5. Make sure to connect Office 365 to your email system.
  6. Transfer your mailboxes.
  7. Begin the staged migration process in batch.
  8. Convert on-premises mailboxes to mail-enabled users for migrating users to their email.
  9. Route your email to Office 365 directly.
  10. Delete the staged migration batch & complete post-migration tasks
  1. IMAP Migration

We’ll not get into the details of the migration task since this method can migrate only emails. And, further, it is suitable if you have very few emails to migrate. To talk about the number of items, then this method supports migrating only 500,000 items from a user mailbox.

  1. Hybrid Migration

 It supports Exchange Server 2010 or later versions. This migration method has the capability to move both on-premises and online mailboxes. 

Let’s see how to move On-premise Exchange mailboxes to Office 365.

  1. Create a migration endpoint
  2. Enable the MRSProxy service
  3. Use the EAC to move hosted Exchange mailboxes
  4. Next, in the EAC, go to Office 365 > Recipients > Migration
  5. Click the Add Icon and select Migrate to Exchange Online.
  6. On the ‘Select a migration type page, choose Remote move migration and hit Next.
  7. Select the users by clicking Add icon and then select the on-premises users to move to Office 365. After that, click Add >OK
  8. Enter the on-premises administrator account name in the On-premises administrator name text field and also enter the associated password.
  9. Verify that the Exchange server is listed when the wizard confirms the migration endpoint.
  10. Provide a name for the migration batch in the New migration batch name text field and from the drop-down menu, select the Target delivery domain for the mailboxes to be migrated.
  11. On the ‘Start the batch’ page, verify that the Automatically start batch option is selected. After that, select the Automatically complete the migration batch check box > click New.

What Challenges You May Face Using The Manual Methods?

The first issue of using this method is that you can only migrate a maximum of 2000 mailboxes. Also, Microsoft recommends migrating 150 mailboxes in batches.

And, after knowing the detailed steps of this type of migration, you can say that it is highly technical. And, demands expertise and knowledge in PowerShell language to execute the scripts. Also, it is very lengthy & will take a lot of time to complete.

Further, you need to enter the cmdlet precisely. Else, there is a chance of data corruption or worst you could lose your valuable data.

Coming to the Staged migration, supports only the 2003 & 2007 Exchange versions of the migration.

Next, using IMAP migration, you can’t migrate the contacts, calendars, tasks, etc.

Last but not least, Hybrid migration needs a complex configuration on the existing on-premise Exchange server and the steps are more complicated than it looks.

Hence, to overcome all these challenges it’s advisable to opt for the automated method and migrate Exchange mailboxes using the tool. By this, you will experience a hassle-free and seamless migration.

Let’s have a look at the detailed procedure of the working of the software.

Software Steps to Migrate Exchange Mailbox to Office 365 Safely

Following are the easy-to-do steps that even a non-technical can perform without any difficulty. Further, there is no fear of accidental data loss and no complicated PowerShell scripts are involved.

Step 1. Download the software by clicking on the given link. Then, run it on your desktop.

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Step 2. After that, navigate to the ‘Set up section. Configure the Source as Exchange and destination as Office 365.


Step 3. Remain on the same page and scroll down. Tick the categories such as Email, Contact, and Calendar checkboxes under the ‘Workload Selection’.


Step 4. You can migrate the selected data of your choice by applying the ‘Date Filter’option.


Then, click the ‘Next’ button.

Step 5. Now, come to the ‘Source’ tab. Provide all the details such as Exchange Server Version, Admin email, Admin Password, Active Directory IP, Exchange Server IP


Step 6. Next, press the ‘Validate’ button to verify the source permission.


Step 7. Once permissions turn green, click on the ‘Next’ button.

Step 8. Similarly, go to the ‘Destination’ Tab. Fill in the Office 365 Admin email and Application ID. After that, verify the destination permissions by pressing the ‘Validate’ button.

And, once it is done, hit the Next button.


Step 9. After that, move toward the ‘Users’ tab. Define the users from the source account. For that, click on any one option among these three: Fetch Users, Import Users, Download Template


Step 10. Now, click on the ‘validate’ button to verify permissions for the Source and Destination.


Step 11. Once you ensure everything is in its place, click on Start Migration to migrate Exchange mailbox to Office 365.


Must Read:  Office 365 Tenant to Tenant Migration Step By Step Solution


To experience the new and advanced work environment, many organizations are switching from an on-premise Exchange to Office 365. However, migrating data between two different platforms is not a piece of cake. 

Though you can migrate your mailboxes using the PowerShell commands, experts always recommend playing safe and trusting the well-versed software to carry out this complex task.