Office 365 Staged Migration – Everything You Need to Know

Admin ~ Modified: October 29th, 2022 ~ Microsoft Exchange Server ~ 12 Minutes Reading

There was a time when organizations used to rely on Microsoft Exchange servers for their day-to-day work operation. But, everything has changed after the introduction of the new cloud technology, i.e. Office 365. Consequently, most organizations tend to incline toward Office 365. Not just to get the benefits of Office 365, but to overcome the limitations of the Exchange server itself. 

Also, as a matter of fact, Exchange 2003 and 2007 servers reached their end of support in 2014 and 2017 respectively. That means no more security upgrades! And, this is the biggest drawback of the Exchange server.

So, if your organization is still using Exchange 2003 or 2007, then it’s high time to think of carrying out a data migration and moving to Office 365. To do so, Office 365 staged migration can be a useful option. So, this technical how-to guide will explain the complete procedure of staged migration for your reference. 

But, before diving into the detailed procedure, let’s know when can you use staged migration and what other things you need to consider.

Essential Things To Know Before Office 365 Staged Migration

When you migrate the contents of user mailboxes from a source email system to Office 365 over time then it’s called a staged migration. Now, let’s have a look at the conditions and considerations of migration.

Mandatory conditions to perform a Staged Migration:

Similar to Office 365 Cutover and hybrid migration, there are a few prerequisites.

  • Your source email system must be Exchange server 2003 or Exchange server 2007.
  • You have more than 2000 mailboxes to migrate to the destination.

What You Should Consider for performing Office 365 staged migration?

  • Use Azure Active Directory sync to synchronize accounts between your on-premises Active Directory domain and Microsoft Office 365.
  • Make sure the primary domain name used for your on-premises Exchange is verified to Microsoft Office 365.
  • You need to recreate the Out of Office messages after the mailbox is migrated to allow Out of Office notifications to be sent.
  • If you limited the connections (such as client/server total connections, per-user connections, and IP address connections) on either server or the firewall. Then, it’s better to increase them for improving the migration performance.

Since the entire migration process will be executed under the supervision of the company administrator, it’s better to be prepared beforehand about the tasks needed to be done as an admin.

Quick Rundown Of Migration Tasks of An Administrator

It’s the responsibility of the administrator to make the migration process successful. So, there are various tasks he/she needs to do at both source and destination end.

Tasks to do at Source End:

  1. Run synchronization
  2. Create a CSV file containing lists of users to be migrated
  3. Convert mailboxes
  4. Create new files for additional batches of users
  5. Perform post-migration tasks

Tasks to do at Destination End:

  1. When you run synchronization, it creates users in Office 365
  2. Execute staged migration batch

[All mailbox items such as emails, contacts, calendars, etc are migrated. And, the migration report is sent to admin.]

  1. Run staged migration batches for additional users
  2. Resolve issues(if any) and delete the migration batch
  3. Carry out post-migration tasks

Since the migration process is very broad, let’s narrow down the complete process and break them into 3 parts.

Also Read About: Office 365 Tenant to Tenant Migration Process

Part 1: Pre-migration Steps To Perform Staged Migration

This part is further divided into various steps. Let’s elaborate on them.

  1. Prepare For The MIgration:
  • Configure Outlook Anywhere(also called RPC over HTTP) to connect to your on-premises Exchange server.
  • Test your connection settings and verify you are connected to your Exchange organization using Outlook Anywhere.
  • Set permissions to access the on-premises mailboxes that you want to move to Office 365.

[Set of permissions include FullAccess and RecieveAs on the on-premises mailbox.]

  • Disable the unified messaging(UM) service. Though, you can turn that back on after the migration.
  1. Verify You Own The Domain:

Making sure you own the domain is also crucial to running staged migration. For that, you can follow the below steps, and further to complete these steps you must be a global admin. 

  • Sign in to your Office 365 account. 
  • Go to Setup and click on Domains.
  • On the next page, click Add domain + to start the domain wizard.
  • After that, select Specify a domain name and confirm ownership.
  • Enter the domain name you use for your on-premises Exchange organization. Then, click Next.
  • To confirm your submission, select your Domain Name System (DNS) hosting provider from the list or select General Instructions, if applicable.
  • Follow the guidelines given by your DNS hosting provider. 
  • Usually, the TXT record is chosen to verify domain ownership.
    So, you can also find the TXT or MX value specific to your Office 365 organization. 
  • Once you add your TXT or MX record, wait about 15 minutes before moving to the next step.
  • At last, in the Office 365 domain wizard choose done, verify now, and after that, you should see a verification page. Click Finish.
  1. Create Users in Office 365:

To create all the on-premises users in Office 365, use either Microsoft Azure Active Directory Synchronization Tool or the Microsoft Azure Active Directory Sync Services (AAD Sync). And, after that, you need to license them.

  1. Create CSV List Containing Mailboxes to be Migrated

The next step is to identify the users whose on-premises mailboxes you want to migrate. Then, prepare a CSV list containing their email addresses, and passwords(optional).

  1. Connect Office 365 to Your Email System

You need to create migrate endpoints in order to connect the on-premise server with Office 365.  Follow the below steps:

  • Go to the Microsoft Exchange admin center.
  • Then, navigate to Recipients >> Migration.
  • Click on More … >> Migration endpoints.
  • After that, on the Migration endpoints page, click on New +.
  • Next, select Outlook Anywhere, and click Next.
  • Now, Enter the on-premises account credentials by typing your Email address, Account with privileges, and Password of account with privileges.
  • After that, press Next. 
  • Then, provide a Migration endpoint name.
  • Finally, click on New to create the migration endpoint.

Part 2: Carry Out Office 365 Staged Migration

After performing the pre-migration steps, let’s come to executing the actual migration. For that, you need to create migration batches. Here, we’ll discuss the ways to create the migration batches in the new Exchange Admin Center(EAC) and in classic EAC.

Since the look and feel are new, the steps to create a migration batch in the new EAC are different from classic EAC.

Let’s have a look at them one at a time.

Create a Staged Migration Batch in New EAC 

  • Open the new Exchange Admin center, and navigate to Migration >> Batch.
  • Click on the New Migration batch and follow the instructions in the details pane.
  • In the Migration Onboarding section, provide the batch name, and choose the mailbox migration path. Then, click Next.
  • Select Staged migration as the type of migration from the drop-down list as shown and press Next.
  • Now, the Set endpoint. So, you can either create a new migration endpoint or select the migration endpoint from the drop-down list.
  • Select and upload a CSV file consisting of all of the users to be migrated.
  • After that, import the CSV file, enter the details and hit Next.
  • Now, Schedule batch migration, verify all the details, and click Save.

Create a Staged Migration Batch in Classic EAC

  • Open the Exchange admin center, go to Recipients, and then click on Migration.
  • Click on the New + >> Migrate to Exchange Online.
  • Now, Select a migration type as Staged migration >> Next.
  • Next, Select the users. For that, click Browse and select the CSV file that you want to use for this migration batch.
  • Then, Confirm the migration endpoint by verifying the migration endpoint information that is listed, and click Next.
  • On the Move configuration page, enter the name (make sure there are no spaces or special characters) of the migration batch, and then press Next. This name is displayed in the list of migration batches on the Migration page once you create the migration batch.
  • Now, you need to specify how you want to start the batch by choosing one of the following on the Start the batch page. The options are:
  1. Automatically: The migration batch will start as soon as you save the new migration batch. It will start with a status of Syncing.
  2. Manually: The migration batch will be created but will not start. Until and unless you start the process manually, the status of the batch will be set to Created. To start a migration batch manually, select the batch from the migration dashboard, and then hit Start.
  • Click New to create the migration batch and it will be displayed on the migration dashboard.

So, if you have created the migration batch and set it to start manually then you need to follow the below steps.

To Start Staged Migration Batch

  • In the new Exchange admin center, move to Migration and click on Batch. On the migration dashboard, click on the batch, and then press Start Migration.
  • In the Classic Exchange admin center, go to Recipients >> Migration. Next, select the batch, and click on Start.
  • To confirm the migration batch starts successfully, check for the status on the migration dashboard, it must be changed to Syncing.

At last, verify whether the migration steps worked or not.

Part 3: Post-migration Steps Of Staged Migration

There are certain things you need to perform after the migration is complete.

Convert On-premises Mailboxes to Mail-Enabled Users

Once you migrate a batch of mailboxes to Microsoft Office 365 successfully, the users will stop receiving new emails in their on-premises mailbox. On the other hand, the users whose mailboxes are migrated are now available on both on-premises and Office 365.

So, you need to direct the emails to Office 365 and for that first, you have to convert on-premises mailboxes to mail-enabled users. Secondly, this needs to be done to retain proxy addresses from the Exchange Online mailboxes by copying proxy addresses to the mail-enabled users. 

Route Emails To Office 365

Generally, Email systems use DNS records called MX records to define where to deliver emails. After the migration, the destination address of the emails is Office 365. So, you must ensure that your MX record is now pointing toward Office 365.

[Note: The above process may take up to 72 hrs to complete, so you need to wait for that much time before proceeding to the next step.]

Delete Staged Migration Batch

Once you change the MX record and verify that all the emails are routed to Microsoft Office 365 and synced, you can delete the staged migration batch. To do so;

  • In the new Exchange admin center, go to Migration and then click on Batch. Then, click on the batch, and press Delete.
  • In the Classic Exchange admin center, go to Recipients and then click on Migration. After that, click on the batch, and hit Delete.

Activate User Licenses

To activate the users at the destination, you need to assign licenses within 30 days of the migration. Otherwise, it’ll be automatically deactivated.

Create an AutoDiscover DNS Record

Make sure to create Autodicover DNS records so that the users can easily find their mailboxes and connect them with Outlook and mobile clients after the migration.

Decommission Exchange Server

Last but not least, you can decommission the Exchange server after the completion of the migration.  But, before that, you must ensure;

  • All the emails are being diverted to the Office 365 environment.
  • You are no longer required to maintain your on-premise Exchange

Challenges of Staged Migration and How To Overcome it?

Clearly, the above steps for performing the migration manually require technical skills and demands expertise in handling the Exchange admin center. 

In addition to that, it is a very lengthy and complicated process. If by mistake, you skip a single step or do it wrong then there is a chance of data corruption or worse data loss.

Besides, staged migration is applicable for only Exchange 2003 and Exchange 2007 servers.

So, alternatively, you can use the Most Trusted Examplery Exchange to Office 365 to easily migrate data between the on-premise Exchange server and Office 365.  

With the help of the tried and tested software, you can effortlessly transfer data from on-premise Exchange to Office 365 in bulk even if you are not from a technical background. Also, it gives you the freedom to re-do the process to fetch the missed items or migrate the newly arrived items.

Above all, the GUI is user-friendly and the migration process is really simple to carry out. With just a few clicks your Exchange server data will transfer to Office 365.

Simple Software Steps Alternative to Office 365 Staged Migration:

Step 1. Download and run the software from the below link.

Download Now Purchase Now

Step 2. Choose the source as Exchange and the destination as Office 365.

Step 3. Provide required credentials for both source and destination.

Step 4. Verify the necessary permission and then Start migration.

Related: How to Transfer Office 365 Mailbox to Another User Account Safely?


With time users are preferring to adopt and keep up with the latest technology. That’s why they are moving their mailboxes from an on-premises Exchange environment to Office 365

Though you can try the Office 365 staged migration method if you want to migrate your Exchange 2003 or 2007 data. But, this manual process is quite lengthy and laborious. Hence, we’ve suggested the automated method which will not only help you carry out the process smoothly but also save you time and effort.