A shared Exchange Server mailbox is a mailbox used by multiple users to access and send emails, or use a common calendar to schedule work shifts. During organizational developments, such as company mergers, restructuring, or platform shifts, migration of a shared mailbox becomes essential. It facilitates better team communication, protects customer data and keeps the teams connected even in a new environment.
For better collaboration, migration of shared mailboxes from the on-premises Exchange server environment to the cloud, such as Microsoft 365 is preferable. Moving on with the topic, this blog focuses on various manual and automated ways to migrate Exchange Server shared mailboxes.
Which Exchange Online is ideal for the migration of shared mailboxes?
Using Exchange Online (Microsoft 365) is a preferred platform to perform migration of shared mailboxes owing to multiple reasons. The table below focuses on some of the prominent reasons:
| Reason | Description |
| Cloud accessibility |
|
| Secure and compliant |
|
| Streamlined collaboration |
|
| Scalable and flexible |
|
| Cost-effective |
|
What are the methods to migrate Exchange Server shared mailboxes to Microsoft 365
Several methods can help to execute this task through Exchange Online, such as:
- Cutover Migration
- Hybrid Migration
- PST-based migration
- Exchange migrator tools
Let’s discuss them in detail.
Cutover migration
This method can help to migrate up to 2000 mailboxes to Exchange Online. But it takes too much time to create and migrate 2000 users. Hence, admins consider it better to move around 150 users.
Preparation for the cutover migration
Before you start the process, make sure to take care of several crucial aspects regarding the cutover migration of the shared mailboxes:
- Verify your on-premises domain ownership in the Microsoft 365 environment
- Set up Outlook Anywhere (RPC over HTTP) on your on-premises Exchange Server
- Get a trusted certification authority (CA) with Outlook Anywhere configuration so that Microsoft 365 can execute a cutover migration.
- Get the necessary permissions to connect to your migration administrator to access the mailboxes that you wish to migrate
- The on-premises user account must have the requisite permissions to access the mailboxes for migration
The Cutover Migration Process
Follow the steps below to perform the migration of shared mailboxes to Microsoft 365.
1. Migration batch creation
Create a migration batch through the Exchange Admin Center (EAC) or PowerShell to start the process. This batch will define the mailboxes that you have to move to the cloud.
2. Migration endpoint configuration
After creating the migration batch, set up a migration endpoint to securely connect the on-premises Exchange Server with Exchange Online. This will enable Microsoft 365 to access the shared mailbox data.
3. Start the migration batch
The next move is to begin the migration, enabling the mailboxes in Microsoft 365 to copy the data of shared mailboxes
4. Progress monitoring
Keep a check on the migration status by using the EAC or PowerShell to confirm the successful migration of the shared mailboxes. Before the migration completes, fix any errors or failed items you come across.
5. Mail flow switching
Update the MX and Autodiscover values in the DNS records. This will divert all incoming emails directly to Microsoft 365 in the place of your on-premises Exchange Server.
6. Access verification and license assignment
This final step requires you to assign the mailbox users the necessary Microsoft 365 licenses. This will allows them gain access to their migrated mailboxes. Also, confirm the right configuration for Full Access and Send As for shared mailboxes.
Staged migration
This migration method suits large organizations that use Exchange Server 2003 or 2007 and have more than 2000 mailboxes. It considers the shared folders as regular user accounts. Instead of moving all the mailboxes at once to Microsoft 365, it performs migration in batches. You may refer to the dedicated Microsoft page for Staged migration to execute the complete method.
Hybrid migration of shared mailboxes
Hybrid migration refers to the migration of mailboxes (including shared mailboxes) from on-premises Exchange Server to the cloud (Exchange Online). It maintains a hybrid configuration through the native Mailbox Replication Service (MRS), which enables both the on-premises and online environments to coexist and perform the migration process together. Some core concepts of this method are as follows:
- Simultaneously retains mailboxes on-premises and in the cloud
- Carries out gradual migration in batches
- Migrates both the user mailboxes and shared mailboxes through the same batch migration process
- Enables the admins and the users to have a unified experience of both environments
- Does not have a limit on the number of mailboxes for migration, unlike cutover migration
You may refer to the dedicated Microsoft page to know the complete process for hybrid migration.
PST-based migration
This method requires you to export the shared mailboxes to PST files and then use the network upload feature to import the PST files you just exported.
1. Export the shared mailboxes to PST files
For this task, use the PowerShell cmdlet New-MailboxExportRequest as given below:
PS C:\> New-MailboxExportRequest -Mailbox Administrator -FilePath \\SRVR01\Export\Admin.pst
Next, track the status of the export request by running the Get-MailboxExportRequest cmdlet.
PS C:\> Get-MailboxExportRequest
2. Import the PST files using network upload
The crucial aspects regarding this specific method are as follows:
- It uses a Shared Access Signature or SAS URL, which is a secure and time-bound link to network upload PST files into Microsoft 365 mailboxes.
- You need to download the AzCopy command-line tool. It facilitates uploading PST files to Microsoft 365 through the import page in the Microsoft Purview portal.
- You must have the required permission to access the portal and proceed with the import job.
Once you fulfill all the requirements, follow the steps below:
-
- Open the Exchange Online portal with your administrator credentials
- Open Compliance portal
- Navigate to Data lifecycle management > Microsoft 365 > Import
- Click + New import job to create an import job
- Name the import job and choose Upload your data
- Click on Show network upload SAS URL and copy the link
- Upload the data with the help of the AzCopy tool
- Create a CSV file that includes mapping information of the PST files to the shared mailboxes
- Monitor the import page through the Microsoft Purview Portal.
These manual methods to migrate Exchange Server shared mailboxes are prone to error and consume considerable time. To avoid such hassles, admins prefer looking for automated alternatives.
Using the Exchange migrator tool
As a suitable option, experts use several Exchange migration tools. These applications are quick and easy to use. Here are some of the common features of the various such applications available online:
- Shared mailbox migration from Exchange Server 2010 and above versions to Exchange Online
- Migration support for public folders and shared, user, and archive mailboxes
- Real-time dashboard to check the migration process
- Parallel processing for seamless migration
- Customizable date-based migration
- Automated mailbox mapping and priority-based migration
- Automatic resumption for a smooth and reliable migration
Of the many tools used online for migration of shared mailboxes, Stellar Migrator for Exchange is a viable option. The software provides all the crucial features required for reliable, quick, and hassle-free mailbox migration.
Conclusion
You may need to migrate your company’s shared mailboxes during several organizational changes, like restructuring, mergers, or platform migrations. It helps to retain smooth communication across different teams within an organization and with its stakeholders. Exchange Online is a suitable platform for migration owing to the cloud accessibility, scalability, flexibility, security, compliance, and several other advantages it ensures.
To perform the migration, you may use several methods, such as Cutover, Staged, and Hybrid migration, depending on the number of mailboxes you want to move to Microsoft 365. Besides, you may also opt for PST-based migration that requires you to export the shared mailboxes to PST and then import the PST files to Microsoft 365 using network upload.
If you find these methods cumbersome and prone to error, you may also use several Exchange migrator tools to serve this purpose. Stellar Migrator for Exchange is a feasible alternative in this regard. It helps to migrate Exchange Server shared mailboxes quickly and without hassles.
