How to Migrate Public Folders of Exchange 2013, 2016, 2019 to Office 365?

Public folders are one among the main constituents of Exchange database. During user-migration from on-premises Exchange to Office 365, administrators got to transfer user mailbox data and public folders. This blog post highlights the three methods for migrating public folders in Exchange 2013, 2016, and 2019 and their comparison. Choose the simplest method as per requirement.

Mailbox migration from on-premises Exchange server to Office 365 must also include migration of public folders. Reason being it contains important information associated with workgroup, list and therefore the organization. However, a Public folder may be a native mailbox of on-premises Exchange and is delegated as a folder within the assigned user mailbox. That’s the rationale it’s to be migrated separately and not with any specific mailbox, during a user migration from on-premises Exchange to Office 365.

The following methods are often wont to migrate Exchange 2013, 2016, 2019 Public Folders to Office 365:

1. Using PST export and migration
2. Using specialized EDB to PST converter software like Converter for EDB
3. Using PowerShell scripts on Exchange on-premises and Exchange online

Let’s discuss the benefits and limitations of every method, which can help choose the simplest method for migration of public folders to Office 365, as per the need .

Comparison of the 3 Methods to Migrate Public Folders of Exchange 2013, 2016, 2019 to Office 365

Methods	PST export and migration	Specialized software – Converter for EDB	PowerShell scripts on Exchange on-premises and Exchange online
Advantages	Manual process Can be performed without third-party software	Simple three-step process: Select-Scan-Export Migrates public folders from offline Exchange Server Migrates public folder of all sizes Less time taking. Time for migration depends upon the size of public folder	Manual process Can be performed without third-party software
Limitations	Can be performed by Exchange administrators only as it requires extensive permissions on on-premises and online Exchange On-premises public folder hierarchy should not exceed the size of 30 GB Public folder permissions are lost when you export it to a PST file Not successful in case of complex permissions and for exporting multiple public folders Changes made to the source folder during PST export and migration are lost	Migrates all data of a public folder except permissions	Can be performed by Exchange administrators only as it requires extensive permissions on on-premises and online Exchange Lengthy and extensive process Process will not be completed in case of even a small change No surety that the migration will be 100% successful even after performing all the steps

Once you’ve got decided the simplest method to migrate Exchange public folders to Office 365, click on the link below to see the steps of the chosen method:

1. PST Export and Migration

Export public folder to PST:

• Open Outlook
• Click File and Open & Export, followed by Import/Export
• From Import and Export Wizard, select the choice Export to a file followed by Next
• In Export to a file window, select Outlook file (.pst) and click on Next
• In Export Outlook file window, select the general public folder to export and click on Next

Select the checkbox for Include Subfolders to incorporate all subfolders of the chosen public folder

• Browse and choose a location where you would like to export PST file
• Click Finish and public folder are going to be exported as PST file at specified location

Note: Not feasible for public folder for size >30 GB.

Migrate PST to Office 365:

• Download the migration script: ps1
• Create a CSV file and map source public folders to those on Office 365
• Create public folders on Office 365 based upon the mapping file
• Create top most public folder in each public folder mailboxes by using New-PublicFolder cmdlet
• Export PST files and import them on Office365 by using Outlook
• Assign public folder permissions with the assistance of Exchange Administration Center (EAC)

2. Migrate Public Folder by using Converter for EDB

• Download and Launch Converter for EDB software
• Select EDB file with public folders and click on Next

The software will scan EDB file and preview it

• Select the checkbox for Public Folders that you simply want to export
• within the main menu, click Save
• From Save window, click Office 365 and supply user credentials

The software successfully migrates Exchange Public Folders 2013, 2016, 2019 to Office 365.

Note:

• This is often the simplest and fastest method of migrating Exchange public folders to Office 365.
• Helps in migrating public folders from offline Exchange.
• If you would like to assign permissions while migration, use the subsequent PowerShell cmdlet-based method.

3. Migrate Exchange Public Folders to Office 365 by using PowerShell Scripts

Office 365 may be a suite of services offered by Microsoft and hosted within their own datacenters across the world . This suite includes Exchange Online, therefore the methods for Exchange online are applicable to Office 365.

Note: Manual migration of recent public folder applies to Exchange 2013, 2016 and 2019 (Public folders till Exchange 2010 are called legacy public folders). Supports all versions of 2019, and requires Cumulative Update CU15 or later, in Exchange 2016, 2013 for on-premises environment.

Prerequisites for migrating public folder to Office 365:

• Lookout that migration is performed within the same Active Directory forest and not a cross-forest migration.
• Take under consideration all limits and performance considerations of public folders.
• In Office 365, Exchange administrator must be a member of Organization Management role group. This permission is different from the one assigned during subscribing to Office 365.
• For migrating public folders from Exchange 2010 and later, Exchange administrator must be a member of Organization Management or Server Management RBAC role group.
• Make sure the dimensions of single public folder is not any quite 25 GB. If the dimensions exceeds 25 GB, either delete the content or divide the content into multiple small public folders.
• Make sure that the method of user migration is complete before migrating public folders.
• Make sure that the firewall permits the IP range employed by Office 365 accounts.
• Verify that administrator is connected to Exchange online by using remote PowerShell.
• Migrate all public folders during a single batch as migration of multiple batches may end in error.
• In Active Directory (AD), make sure the following:
• No public folder mail objects are orphaned on AD
• SMTP email addresses are same for public folder on AD and Exchange objects
• There’s no duplicate public folder in AD. No two AD objects must point to same mail-enabled public folder
• Make sure that there’s enough bandwidth for Exchange Server downtime, as downtime is must to execute a couple of migration steps. At this point , public folders will remain inaccessible for usage.

Steps to Migrate Exchange Public Folder to Office 365

1. Download the scripts

Download the scripts and supporting files and save them locally on the pc on which you’ll run PowerShell cmdlet. These scripts are available on Microsoft online website for end users. Just visit ( https://go.microsoft.com/fwlink/p/?linkid=844893 ) and are meant to sync, export and map modern public folder statisticsPrepare Exchange for migration.

2. Prepare Exchange for migration

Run Source Side Validation Script available on on-premises Exchange server.

In Exchange Management Shell of on-premises Exchange Server, perform the following:

• Direct DNS caches to send messages to mail-enabled public folders in their location at Office 365. To enable this on Office 365, configure a send connector by the Hybrid Configuration Wizard.
• If the accepted name is already listed in on-premises Exchange, then rename it and lookout to not change the other attribute.

Note: Backslash \ and forward slash / aren’t accepted during migration, so remove these characters from the name of public folders and rename them.

Check for any previous migrations and their status. If it returns with a worth set as $true, then set its value as $false.

3. Take snapshots

To ensure that the migration process is complete and successful, take snapshots of current public folder deployment with the assistance of PowerShell cmdlets. These snapshots help in comparing with newly migrated public folders. Take snapshot of the following:

• Original source folder structure
• Public folder statistics like its owner, item count, etc.
• Permissions
• Mail-enabled public folder

Save these snapshots at a secure place for comparing at the top of migration.

4. Remove all public folders in Office 365

Note: make sure that the knowledge contained in these folders is saved at a secure location. Once, you’ve got removed all public folders, remove all public folder mailboxes.

Once the on-premises Exchange server is prepared , perform the subsequent steps on Office 365 or Exchange online PowerShell:

• If any migration request is in pipeline, discover and take away any existing migration request.
• Also, check if any public folder mailbox is out there . However, this could not return with a positive result.
• If there are any public folder mailboxes available, then remove them after checking for any saved information.
• Next, run public folder mailboxes.

5. Generate CSV files

• On Exchange Management Shell (EMS), run the script Export-ModernPublicFolderStatistics.ps1 to make folder name to folder size mapping file. this may also help in verifying the dimensions of public folder to be exported.
• Next, run the script: ps1 to make a .csv file which will map the source public folders in on-premises Exchange server to public folder mailboxes in Exchange Online destination. It also helps in calculating the entire number of public folder mailboxes in Office 365.
• The utmost mailbox size for one folder in bytes is 50 GB. Assign a maximum of fifty size to the mailbox to make sure space for future growth.
• It’s recommended to stay the utmost size of recoverable items quota publicly folder mailboxes to fifteen GB or less.

Note: you can’t migrate quite 100 unique public folder mailboxes to Exchange online.

6. Create target public folder mailboxes on Exchange online

Create target public folder mailboxes which will contain migrated public folders. an in depth information of those folders is out there in .csv file.

7. Start migration request

On on-premises environment and in Exchange Online, perform the following:

On Exchange 2016 or Exchange 2019 source servers, synchronize mail-enabled public folders from your local Active Directory to Exchange Online

Note:

• Make sure the downloaded script is of the newest version and run the script from Exchange Management Shell (EMS).
• Use Exchange Online administrator user name and password as credentials.
• Attend on-premises Exchange and open EMS. Locate GUID of the first hierarchy mailbox. Check the output of this PowerShell command because it is required within the next step. In Exchange Online, create the general public folder migration endpoint and therefore the public folder migration mapping.
• There’s an opportunity that map file has moved to a replacement location, then use the new location.
• Separate multiple mailbox addresses with commas
• Note: you’ll receive a mistake that states, a parameter can’t be found that matches parameter name ‘SourcePfPrimaryMailboxGuid’, then create the migration batch
• Finally, start the migration process in Exchange Online PowerShell with the assistance of ‘Start-MigrationBatch PublicFolderMigration’ command
• Before moving on to next step, lock the general public folders on the Exchange on-premises server and verify that each one data is copied without error
• Once you’ve got confirmed that the batch has moved to the state of Synced, steel oneself against the migration within the final step under Prerequisite steps within the Exchange Server on-premises environment, to require a snapshot of the general public folders on-premises
• Once these commands have run, you’ll proceed to subsequent step. These commands may take a touch long to finish and depends on the amount of folders. Every 24 hours, this migration process synchronizes the info from on-premises environment
• You’ll monitor the migration process with the assistance of following requests:

Get-PublicFolderMailboxMigrationRequest

Get-PublicFolderMailboxMigrationRequestStatistics

Get-MigrationBatch

8. Lock the general public folders on the Exchange on-premises server (requires public folder downtime)

Until now within the migration process, users are ready to access on-premises public folders. the subsequent steps will now sign off users faraway from Exchange Server public folders then lock the folders because the migration process completes its final synchronization. Users won’t be ready to access public folders during this point , and any messages sent to those mail-enabled public folders remain undelivered until the migration process is complete.

Note: the ultimate sync may take some amount of your time , counting on the subsequent factors – changes in source environment, size of the deployed public folder, server capacity, etc. Therefore, schedule a minimum of 48 hours of downtime.

• Make sure the migration batch and individual migration requests are synced.
• The LastSyncedDate (on migration batch) and LastSuccessfulSyncTimestamp (on individual jobs) should be within the last 7 days. If the date is just too far within the past, like quite a month ago, you would possibly want to review public folder migration requests and make sure that all the requests were synced recently.
• After you’ve got confirmed that the batch and every one migration requests have successfully synced, in your on-premises environment, lock the Exchange Server public folders for finalization.

Note:

Sometimes, Active Directory may take quite the stipulated time. Then, there’s no way you’ll access the -PublicFolderMailboxesLockedForNewConnections parameter, during the CU upgrade.

For organizations, having public folder mailboxes on multiple Exchange servers, wait until Active Directory replication is complete.

• Once the method is complete, you’ll confirm that each one public folder mailboxes have picked up the PublicFolderMailboxesLockedForNewConnections flag, which any pending changes made to the general public folders have converged across the organization. it’s going to take several hours.

9. Final steps for public folder migration (requires public folder downtime)

• Before final completion, make sure there are not any other public folder mailbox moves or public folder moves happening in your on-premises Exchange environment.
• Re-run the subsequent script to see if any new mail-enabled public folder is synchronized with Exchange Online:
• .\Sync-ModernMailPublicFolders.ps1 -Credential (Get-Credential) -CsvSummaryFile:sync_summary.csv
• Finally, complete the migration by running the ‘Complete-MigrationBatch PublicFolderMigration’ command in Exchange Online.

Note: there’s no scope of knowledge sync after the migration process is completed

• once you run Complete-MigrationBatch PublicFolderMigration command, Exchange will perform a final synchronization between on-premises Exchange and Exchange Online. During this era , the status of the migration batch will change from Synced to Completing, then finally to Completed.

10. Test and unlock public folders in Exchange Online

Perform the subsequent steps to check the success of public folder migration. These final tasks allow you to check the migrated public folder hierarchy before you permanently switch to Office 365 public folders.

• attend Exchange Online PowerShell, configure a test user mailbox to use as newly migrated public folder mailbox as default.
• Provide all necessary permissions to make public folders.
• go online to Outlook with the test user account and . await 15 to half-hour for the changes to require effect. Once Outlook recognizes the changes, test the user account. it’d prompt to start out Outlook. Once done, check the subsequent View folder hierarchy.
  b. Check permissions.
  c. Create and delete a couple of public folders.
  d. Post and delete content from a public folder.
• In Exchange Online PowerShell, run the cmdlet to unlock public folders in Exchange Online. await 15 to half-hour for the changes to require effect. Once Outlook recognizes the changes, it’d prompt to start out Outlook.

11. Finalize the migration on-premises

To enable emails to mail-enabled public folders on-premises, perform the subsequent steps:

• Take a backup of emails within the queue that were sent to mail-enabled public folders. This backup is beneficial when email delivery to mail-enabled public folders has failed.
• On on-premises environment, make sure that the emails to mail-enabled public folders are routed to Exchange Online.
• On on-premises environment, test that the general public folder migration is successful and complete.

12. the way to test that public folder content has migrated completely?

Compare the info with the previous snapshots to verify success. attend Exchange Online and take the subsequent snapshots for comparison:

• New folder structure
• Public folder statistics, including item count, size, and owner
• Permissions
• Mail-enabled public folders

Conclusion

This post focuses on three methods of migrating Exchange 2013, 2016, 2019 public folders to Office 365 and their comparison. This comparison can act as a deciding factor for you to pick the simplest method as per your requirement.

To summarize, migrating through PST export may be a short method but it doesn’t migrate the folder permissions. Also, it migrates public folders of size but 30 GB and doesn’t export multiple folders.

Converter for EDB helps Exchange administrators to export public folders when the Exchange Server isn’t accessible or available in offline state. Also, the software exports all EDB mailboxes to Office 365 or Exchange online account.

PowerShell script method is lengthy and involves server downtime, which can disrupt the business continuity. If your Exchange administrator team is looking to revive user mailbox data from locally saved offline folder file, then you’ll take assistance of OST to PST converter .