How to migrate public folders to Office 365: Top Solutions!

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Summary: Want the proper method to migrate public folders to Office 365 with zero % data loss? Use Microsoft’s migration script & Outlook application to execute the process. Moreover, opt for the advanced Migration for Office 365 tool for instant results and complete assistance.

Public folder creation helps users reduce the timeframe of accessing the same content among subordinates of the same level. However, in some instances, on-premises users need to move public folders to Office 365, which helps them access the content from anywhere with some additional benefits.

So, here, our expert guidance will help you get all the relevant information you need to know before, after & during the o365 public folder migration. Let's start our discussion to know how to access public folders in Outlook 365.

Migrate public folders to Office 365: Why?

There can be several reasons for moving public folders to Office 365, but the prominent ones that enhance the overall user experience with efficient output are mentioned below:

  • Accessibility of public folders between on-premises & online is one way that creates the need for migration.
  • Through enhanced security, office 365 provides future safety for the user's data from several threats.
  • Since their data is stored on the cloud, it can be retrieved easily if corrupted or damaged.
  • Using Office 365 opens multiple doors for opportunities, such as advanced collaboration.
  • After migrating, organizations can reduce the burden of maintaining mailbox data.
  • Office 365 scalable & flexible features allow users to manage their business as per their needs.

Note: Users should execute the public folder migration to Exchange Online only after migrating all users' mailboxes to Exchange Online.

Proven methods to migrate public folders to Office 365!

After several hits & trials, we have provided the best possible methods that can help you to move public folders to Office 365. So, follow them carefully.

Solution 1. Try Microsoft’s migration script for o365 public folder migration

The migration script is one of the best manual approaches to migrating public folders to Office 365. In this method, we will use Exchange Management Shell on Exchange servers, whereas Exchange Online PowerShell in Exchange Online.

Executing it requires too much user’s attention. So, check out the Microsoft 365 migration checklist before the migration to ensure data security. After that, delve into the steps to accomplish the task successfully:

Step 1. Download all the required migration scripts and supporting files from the given source and save them on your local system, on which you will use PowerShell.

Note: Use the Source Side Validation script for on-premises Exchange Server. It will scan and report issues that may cause slow migration.

Step 2. Check out the following prerequisites in the on-premises Exchange server environment.

  • Create an accepted domain with a well-known name to ensure your newly migrated mail-enabled public folders receive messages during the DNS transition period.
  • Rename folders with a backslash or a forward slash in their name to remove these characters.

Step 3. Complete the following prerequisites in Exchange Online to ensure a successful migration.

  • Clear the remaining o365 public folder migration request in the pipeline.
  • Ensure that there aren’t any existing public folders in Exchange Online. If they are found, remove them by running the provided command in PowerShell.

    Get-MailPublicFolder -ResultSize Unlimited | where {$_.EntryId -ne $null}| Disable-MailPublicFolder -Confirm:$false Get-PublicFolder -GetChildren \ -ResultSize Unlimited | Remove-PublicFolder -Recurse -Confirm:$false

  • For public folders mailboxes, you can run the given command & repeat it a couple of times at intervals of five minutes to ensure that all SoftDeletedMailboxes are cleared up & there are no CNF objects left behind.
  • Run the following to confirm that all SoftDeleted or CNF mailboxes get deleted.

Get-Mailbox -PublicFolder -SoftDeletedMailbox

Step 4. Generate the CSV files by using the previously downloaded scripts to use them in the migration.

  • Run command in the Exchange Management Shell (on-premises) to create the folder name-to-folder size mapping file.

    .\Export-ModernPublicFolderStatistics.ps1 <Folder-to-size map path>

  • Users can also run the following script to create the .csv file, which helps them map source public folders to public folder mailboxes in their Exchange Online destination.

    .\ModernPublicFolderToMailboxMapGenerator.ps1 <Maximum mailbox size in bytes><Maximum mailbox recoverable item size in bytes><Folder-to-size map path><Folder-to-mailbox map path>

Note: Users can migrate up to 100 unique public folder mailboxes while moving public folders to Office 365.

Step 5. Using the Exchange Online PowerShell, create the target public folder mailboxes to store your migrated public folders. To achieve this, you can run the provided script. It will create the target mailbox for individual mailboxes in the .csv file.

$mappings = Import-Csv $primaryMailboxName = ($mappings | Where-Object FolderPath -eq "\" ).TargetMailbox; New-Mailbox -HoldForMigration:$true -PublicFolder -IsExcludedFromServingHierarchy:$false $primaryMailboxName ($mappings | Where-Object TargetMailbox -ne $primaryMailboxName).TargetMailbox | Sort-Object -unique | ForEach-Object { New-Mailbox -PublicFolder -IsExcludedFromServingHierarchy:$false $_ }

Step 6. It's time to start the migration request. To accomplish this, you must run the number of commands in both Exchange Server on-premises & in Exchange online. Let's start one by one:

  • From the Exchange Server hosting public folder mailboxes, execute the following script, which will synchronize mail-enabled public folders from your local Active Directory to Exchange online.

    .\Sync-ModernMailPublicFolders.ps1 - CsvSummaryFile:sync_summary.csv

  • Now, in the Exchange Online PowerShell, pass the credentials of the users who have the administration permissions in the Exchange Server on-premises environment by running the following command:

    $Source_Credential = Get-Credential <source_domain>\<PublicFolder_Administrator_Account>

  • Further, you have to pass the Internet routable fully qualified domain name of your Exchange Mailbox Replication Service (MRS) in the Exchange Online PowerShell by executing the given command:

    $Source_RemoteServer = "<MRS proxy endpoint server>"

  • In the on-premises Exchange Server, use the provided command in the Exchange Management Shell to find the GUID of the primary hierarchy mailbox. Note the output, as it will be used in the next steps.

    (Get-OrganizationConfig).RootPublicFolderMailbox.HierarchyMailboxGuid.GUID

  • Run the following commands to create the public folder migration endpoint & the public folder migration request in the Exchange Online PowerShell

    $bytes = [System.IO.File]::ReadAllBytes('folder_mapping.csv') $PfEndpoint = New-MigrationEndpoint -PublicFolder -Name PublicFolderEndpoint -RemoteServer $Source_RemoteServer -Credentials $Source_Credential New-MigrationBatch -Name PublicFolderMigration -CSVData $bytes -SourceEndpoint $PfEndpoint.Identity -SourcePfPrimaryMailboxGuid <guid you noted from previous step> -NotificationEmails <email addresses for migration notifications>

    • Note: Provide each detail with utmost care & separate multiple email addresses with commas.

  • Finally, run the given command in the Exchange Online PowerShell to start the migration process.

Start-MigrationBatch PublicFolderMigration

Optional step: You can view the status of these requests using the mailbox migration page by following the given steps:

  • Access the Exchange admin center, select the Migration option.
  • Choose the created migration request, go to the Details page, and select View Details.

Step 7. Public folders on the Exchange on-premises server should be locked. This will restrict users' access to the Exchange Server Public folders and lock the folders until the public folders migration to Office 365 process completes its final synchronization.

After confirming that the batch & all migration requests have successfully synced, run the following command in your on-premises environment to lock the Exchange server public folders for finalization.

Set-OrganizationConfig -PublicFolderMailboxesLockedForNewConnections $true

Step 8. To complete the public folder migration to Exchange Online, users must ensure that there are no other public folder mailbox moves or public folder moves in their on-premises Exchange environment.

Step 9. Finally, run the given command in the Exchange Online PowerShell to complete the migrate public folder to Exchange Online process.

Complete-MigrationBatch PublicFolderMigration

It may take some hours to change the status from synced to completed. However, before opening the folders to the users, you need to go through the next steps.

Step 10. Here are some workarounds that users need to perform to test the migration's success and officially verify its completion.

  • After providing the necessary permissions to test users, configure them to use one of your newly migrated public folder mailboxes as their default.

    Set-Mailbox -Identity <test user> -DefaultPublicFolderMailbox <public folder mailbox identity>

  • Access the Outlook application with the same test users as above & perform the following public folder tests as view the hierarchy, check permissions, create some public folders & then delete them, post content to, and delete content from, a public folder.
  • Changes may take some time to take effect. If you don’t have any issues, you can follow the next steps; otherwise, you have to roll back to the previous steps.
  • Run the provided command to unlock your public folders in Exchange online:

    Set-OrganizationConfig -RemotePublicFolderMailboxes $Null -PublicFoldersEnabled Local

Note: For safety reasons, it is recommended that you back up your emails that can be executed by the provided command in your on-premises environment.

$Server=Get-TransportService;ForEach ($t in $server) {Get-Message -Server $t -ResultSize Unlimited| ?{$_.Recipients -like "*PF.InTransit*"} | ForEach-Object {Suspend-Message $_.Identity -Confirm:$False; $Temp="C:\ExportFolder\"+$_.InternetMessageID+".eml"; $Temp=$Temp.Replace("<","_"); $Temp=$Temp.Replace(">","_"); Export-Message $_.Identity | AssembleMessage -Path $Temp;Resume-message $_.Identity -Confirm:$false}}

Step 11. Run the following script in the on-premises environment to ensure all emails to mail-enabled public folders are correctly routed to Exchange Online.

.\SetMailPublicFolderExternalAddress.ps1 -ExecutionSummaryFile:mepf_summary.csv

Step 12. Now, once all testing is successful, run the provided command in your on-premises environment to indicate that the public folders migration to Office 365 is completed.

Set-OrganizationConfig -PublicFolderMailboxesMigrationComplete:$true -PublicFoldersEnabled Remote

Solution 2. Migrate public folders to Office 365 using the Outlook application

Users can move public folders to Office 365 using Outlook’s import & export facility. With this utility, users export their public folders in PST form, and then they are imported into Office 365 for use in Office 365. However, users should prefer this method as the last recourse.

Important to know:

Exchange Online uses the Auto split feature to manage the public folder mailboxes. However, the sudden growth of public folders and mailboxes will not be easily manageable as it will lead to waiting for two to three weeks for further processing, along with other impactful setbacks.

Hence, it is not recommended to go for these methods & if you are looking for it, then the on-premises public folder hierarchy should not be over 30 GB.

Manual methods look complex! Explore the best alternate solution now!

As you see, manual methods might not be helpful in giving instant & accurate results with data security assurance. Moreover, they lead to create data loss instances if any steps are performed wrong. So, to avoid these situations, experts follow advanced migration for Office 365 tools that provide them safe & secure migration instantly.

Recoveryfix Migration for Office 365 stands out as the top choice in this category with its structured or versatile features. It migrates all components, including the Archive mailbox, public folder, etc., to Office 365, and its innovative filters help users get specific results as needed. Even Exchange 2016 public folder migration to Office 365 can be possible with this advanced tool.

Conclusion

Migrate public folders to Office 365 using the methods provided in the blog. Go through them one by one & try to follow the given steps in the correct order to avoid any ambiguity.

Moreover, if you want quick & error-free results, go for the suggested advanced tool. For a hands-on experience, check out its free trial version.