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Summary: This article explores methods for exporting linked mailboxes from Exchange 2010 to Office 365, highlighting the challenges of manual migration and the use of third-party solutions like Kernel Migration for Exchange for a seamless transition. Manual migration involves complex PowerShell cmdlets, while the tool offers a user-friendly alternative.

This article exclusively centers on the methods for exporting linked mailboxes from Exchange 2010 to Office 365 . It aims to assist both Exchange and Office 365 users in discovering the most effective migration solution. The migration process between Exchange Server 2010 linked mailboxes and Office 365 offers two viable approaches: a manual solution or the utilization of specialized third-party software.

Prior to initiating the migration of Exchange linked mailboxes, it’s essential to have a clear understanding of what linked mailboxes entail within the Exchange Server context. Linked mailboxes are essentially mailboxes that are associated with accounts located outside of a given forest. In this scenario, user objects are tethered to user mailboxes but lack the ability to access logon services. To facilitate access to these logon services, the expertise of an Exchange administrator is necessary to establish the necessary links between mailbox objects and user objects.

So, as we understood the basic concept of linked mailboxes in Exchange account, let us move ahead with the migration process.

Native Method to Migrate Exchange 2010 to Office 365

In the process of manually migrating Exchange 2010 linked mailboxes, it becomes essential to transform these linked mailboxes into standard user mailboxes since a direct migration to an Office 365 location is not feasible. This conversion of linked mailboxes into Exchange user mailboxes can exclusively be executed by executing specific cmdlets within the Exchange Management Shell.

  1. Assign permissions to the user account by these cmdlets –
    New-ManagementRoleAssignment -Role “Mailbox Import Export” -User “Domain\UserName”
  2. Now, convert linked mailboxes to user mailboxes by setting LinkedMasterAccount parameter as null –
    Set-User -Identity -LinkedMasterAccount $null

Now, those linked mailboxes are converted to user mailboxes; you can further use the cut-over migration method to convert Exchange 2010 user mailboxes to Office 365.

Challenges With the Manual Way
  • Not a direct migration (2 way)
  • Complicated and much technical
  • Quite lengthy to perform
  • Good chances of errors
  • Unreliable for complex migrations

These limitations are not to be underestimated. Therefore, it is advisable to consider employing a dependable migration solution when transitioning linked mailboxes from Exchange 2010 to Office 365. This can be achieved through the use of third-party software that excels at performing seamless migrations in a single operation, all while offering an intuitive and user-friendly interface.

Migration with Kernel Migration for Exchange

Kernel Migration for Exchange stands as the ultimate Exchange migration solution, seamlessly enabling migrations across various Exchange versions, as well as between Exchange versions and Office 365, Office 365 and Exchange versions, and even between Office 365 tenants.

You can perform migration from Exchange 2010 to Office 365 with these steps:

  1. Launch the software and click Add Job for Mailbox, then enter the Project Name, Job Name and click Next.
  2. Now, select Exchange Server as the source, enter its IP address, User Name, password, etc. and click Exchange Server as the source
  3. Select the mailboxes from the list you want to migrate and then click Next.Select the mailboxesNote: You can also import the list of mailboxes from a CSV file.
  4. Now, select Office 365 as the destination. Provide its credentials and click Next.Select Office 365 as destinationNote: You can also delegate full access rights to the user by selecting the option.
  5. Now set filters like Message classes, date range, folders filters according to your need. Then click Next.set filters
  6. Here, map the source and destination mailboxes, then click the source and destination mailboxes
  7. In the next steps, the user can manage bad items and synchronization, set notifications, allot/deny hours for migration, schedule migration job, set report console, etc. Click Finish to migrate.
  8. Within some minutes, the migration is completed, and the final report is shown report


Migrating Exchange-linked mailboxes to Office 365 can be a daunting endeavor when opting for the manual approach. This method involves the utilization of intricate PowerShell cmdlets, making the process time-consuming and intricate. Alternatively, an efficient and dependable solution for Exchange to Office 365 migration is Kernel Migration for Exchange.

Kernel Migration for Exchange