Migrating Exchange on-premises Public Folders to Office 365

Public Folder in Microsoft Exchange environment works as a root hierarchy to provide shared access and helps in easily browse, collect, and organize information in the work group. Working with Microsoft Outlook, you can easily view public folder hierarchy and select the other content you’re interested in. As public folder can be also accessed in Office 365 and OWA, so you can also easily migrate the existing on-premises Exchange public folder to Office 365 account.

So today we’re sharing the quick steps to easily migrate public folders into Microsoft Office 365. Follow the migration steps-

• If there are more than 100 folders in public folder hierarchy, then reduce it because Exchange Online only allow 50 numbers of folder to be migrated. If you want to migrate more than the limit, contact Microsoft Support team.
• Now primarily, only migrate user’s mailbox to Office 365 then public folders.
• Now enable Outlook Anywhere on Exchange Server (on-premises) and execute the shell command to copy the existing folder structure. Once the migration is completed, it serves as verification.
•     Create a CSV mapping file which contain folder-to-size and folder-to-mailbox records.
• Now create public folder mailboxes using Powershell command in remote session mode, or open Exchange Online to create PF mailboxes.         
• Now migrate folder using the *-MigrationBatchcmdlets
• Lockdown public folder until synchronization is completed with Exchange Online. During the synchronization, there will be no access to public folder until the synchronization processis finished.
• Now check the accuracy of the migration by selecting a mailbox. Test all the action to check the correctness - you can create and delete folders, you can create items in the folder, and also check the permission and the complete hierarchy.
• Once you’ve checked the correctness of public folder, unlock it from the other mailboxes.
• Now again verify the correctness of migration, and also match the folder hierarchy structure from the copy of source server(on-premises Exchange Server)  with the current folder structure of Exchange Online.
• That’s it. Now you can remove public folder database from the on-premises Exchange Server.

As you can see the process is bit complicated because of the heavy use of Powershell scripts, so you will need to connect Office 365 using remote Powershell for the migration. 

    However if you want to eliminate all the manual migration steps; there is a most sophisticated option available for public folder to Exchange Online migration. Just download Stellar Mailbox Extractor for Exchange Server and simply migrate Exchange Server public folders and mailbox database to Office 365. That’s it.