How to Migrate Public Folders to Office 365 – My Proven Process

Written By Mohit Kumar Jha

Approved By Anuraag Singh

Modified On July 17th, 2025

Reading Time 5 Minutes Reading

Migrating public folders to Office 365 is essential if you’re moving away from on-premises Exchange. Recently, I completed this migration, and now I’m here to guide you on how to migrate public folders to Office 365 without losing data.

Why I Performed Public Folder Migration to Office 365

For me, the decision came down to three things:

Centralised access from anywhere
Reduced maintenance of on-prem Exchange servers
Enhanced security capabilities in Microsoft 365

But migrating public folders isn’t a straightforward procedure, as it requires technical expertise to run PowerShell commands and follow prerequisites. Don’t worry at all, I’m here to simplify things for you. Let’s start with pre-migration steps.

Pre-Migration Requirements to Migrate Public Folders to Office 365 Hassle-free

I made sure to take these pre-migration steps:

Source Exchange server is Exchange 2010 SP3 RU8 or later
Ensure the target environment (Microsoft 365) has enough licensing to host public folders
Office 365 has limits that no public folder mailboxes can exceed 100 GB. Additionally, the total public folder hierarchy size must not exceed 1 million folders.

Remove obsolete and empty folders
Fix any permission issues
Remove conflicting aliases and duplicates
Back up the entire mailbox data

Public Folder Migration to Office 365 – Step-by-Step Guide

Microsoft doesn’t provide any native tool for a specific public folder migration. However, when I needed to migrate public folders to Office 365, I found two reliable solutions that work for me:

#Method 1. Using PowerShell

PowerShell is a technical but effective solution, and by following these cmdlets, you can automatically migrate data in one go:

Step 1. Download Microsoft Migration Scripts

These include:

Export-PublicFolderStatistics.ps1
Export-PublicFolderFolderSize.ps1
PublicFolderToMailboxMapGenerator.ps1
Create-PublicFolderMailboxesForMigration.ps1

Step 2. Export the public folder structure:

Get-PublicFolder -Recurse | Export-Csv .\PublicFolders.csv

Step 3. Generate the mailbox mapping file

.\Export-PublicFolderStatistics.ps1 > .\PFStatistics.csv
.\Export-PublicFolderFolderSize.ps1 > .\PFFolderSize.csv
.\PublicFolderToMailboxMapGenerator.ps1 .\PFFolderSize.csv 100000000 > PFMailboxMap.csv

Step 4. Create Public Folder Mailboxes in Office 365 Using Exchange Online PowerShell:

.\Create-PublicFolderMailboxesForMigration.ps1 .\PFMailboxMap.csv

Step 5. Now, migrate public folders to Office 365 by running these commands:

New-MigrationBatch -Name "PublicFolderMigration" `
-SourcePublicFolderDatabase (Get-PublicFolderDatabase) `
-CSVData (Get-Content .\PFMailboxMap.csv -Encoding Byte) `
-NotificationEmails "[email protected]"

Step 6. After verifying the sync percentage reached 95% or more, I locked down the folders on-prem to prevent changes during the final sync:

Set-OrganizationConfig -PublicFoldersLockedForMigration:$true

Step 7. In Exchange Online, I finalised the batch:

Complete-MigrationBatch -Identity PublicFolderMigration

And enabled the public folders:

Set-OrganizationConfig -PublicFoldersEnabled Remote

These commands are genuine, and you can verify them from this official Microsoft site.

When done with the transition, check if the data has been completely migrated to the target platform. For any reason, if your data is not moved properly, then check whether you ran all the commands or not. If the issue persists, then you have to run the entire public folder migration to Office 365 again.

#Method 2. Migrate Public Folders to Office 365 Using a Cutting-edge Solution

As public folders store one of the most important data sets of an organisation, it is always suggested to go with the MVP Recommended SysTools Exchange Recovery Solution. It is one of the most advanced solutions that permit users to migrate mail-enabled public folders to Office 365. You can try this utility for free now!

Here’s why I recommend this:

Allows users to customise the public folder migration as per their needs
Supports date-based filters to migrate only selective mailbox items within a specific time range
Performs deep recovery of public folders, including the ability to recover permanently deleted emails
Enables you to export public folders to PST format without any data loss
Maintains the original folder structure during and after migration
Supports migration to Office 365 and other destinations with complete accuracy

Quick Steps for Public Folder Migration to Office 365

Step 1 – Download software on Windows OS.
Step 2 – Load public folder into tool.
Step 3 – Preview public folder mailboxes.
Step 4 – Choose Office 365 export option.
Step 5 – Click on the Export button.

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Simple Steps for Public Folder Migration to Office 365

Step 1. Launch the software and click on the Add File button.

Step 2. Add the public folder EDB file to the application.

Step 3. The software will now provide a preview of mailbox data.

Step 4. Choose Office 365 as the export option to migrate public folders.

Step 5. Provide O365 account details and validate them.

Step 6. Finally, hit the Export button to start migration.

Despite that, there is another way to migrate public folders to Office 365 using the Outlook PST export option. However, Microsoft itself doesn’t recommend users go with this solution if the public folder hierarchy is more than 30 GB. Additionally, there are chances of data loss if you choose this procedure over the others mentioned in this write-up.

Post-Migration Best Practices

Even after a successful public folder migration to Office 365, it is necessary to ensure the post-migration considerations:

Make sure folder-level access is carried over correctly
Train users on how to access public folders in Outlook Online
Ensure public folder mail-enabled addresses are working
After testing, shut down the on-prem public folder database

Author’s Verdict

The procedure to migrate public folders to Office 365 is quite tricky if you opt for the manual method(PowerShell). I went through this and found that I’m not getting the expected results due to the complex cmdlets involved in the process.

That’s why I opt for the professional utility, which helps me to complete the public folder migration to Office 365 in minimal time without any data loss.

Both solutions are explained in this guide; you can opt for any according to your needs.