Public Folders can only be migrated to other public folders or shared mailboxes. We do not migrate Public Folders to individual user mailboxes or Microsoft 365 Group mailboxes or vice versa. Mail-enabled public folders are not supported for destination endpoints that are Exchange On-Premise and will need to be mail-enabled manually. For additional details about items that are and are not migrated from public folders, see our Migrated and Not Migrated Items article.

Exchange 2010 SP1+ & Microsoft 365

Migrated

• Public Folders
• Subfolders
• User Permissions
• Mail-Enabled Security Group Permissions (Default and Anonymous User Permissions are not supported)

Not Migrated

• Rules

Not Migrated in any Exchange Instance

• Email templates
• Email flags (if the destination is G Suite)
• Safe Sender/Block Lists
• Mail Settings
• Standalone documents stored in Mailbox Folders or Public Folders (Example: IPM.Document item types)
• System Public Folders
• StickyNote folders

Not Migrated in Exchange 2007: Public Folder Permissions

Open a ticket with BitTitan Support

Once you have completed the Run Verify Credentials step, open a ticket with BitTitan Support by following the instructions in How do I get support for your products? Make sure to include the following information in your ticket:

• The subject of the ticket should be “Public Folder SPLIT or Mapping Scripts Needed”
• Make sure to attach the folders.csv file to the ticket from the step above for migrating more than 1,000 folders if one is required.

If you have already submitted a ticket for another issue, simply add the new information to that existing ticket.

1. Grant admin permissions
2. Break up large folders (if required)

Grant admin permissions

• Grant elevated 'Organization Management' administrator role to the migrating administrator account. Refer to Assigning the Elevated Admin Role 'Organization Management' to a Public Folder Account for Migration.
• Ensure that the source administrator account has a mailbox enabled and is located on the same Exchange server as the source Public Folder database or mailbox.
• Ensure that the migrating administrator account has permission in all Public Folders (Read only or "Reviewer" access rights should be enough). For more information, see Granting Necessary Permissions to Source Public Folders.

Break up large folders

You will want to perform these tasks first before beginning your migration. If you are migrating more than 1,000 folders (including sub folders) and/or more than 20GB of data, break these folders up before contacting BitTitan Support.

• Split up large Public Folders: if any source Public Folders contain more than 100,000 items (if Source = O365, Exchange 2010 or later), these should be split into multiple Public Folders as they can cause migrations to be held up with processing of the high number of items. Breaking up these folders can help with faster migration speeds. For more information, see Finding Public Folder Size for Migration. 
• Any individual Public Folders that are over 20GB in size should be split up into smaller folders of 20GB or less. Failure to complete this step can negatively impact migration performance and speed.

The steps listed below apply to both the source and/or destination tenant when they are Exchange Online, in regards to Exchange Web Services (EWS) in mailbox, archive mailbox, and public folder projects. Select the option you wish to use for either your source or destination tenant. Use a Global Administrator to perform the configuration steps.

Important: Failure to perform the steps for your Microsoft 365 endpoints, can result in failed jobs with 401 errors like the following in your project: Http POST request to 'autodiscover-s.outlook.com' failed - 401 Unauthorized

The administrator account being used for the project Exchange Online (Microsoft 365) endpoints needs to be excluded from any MFA/2FA policies or Conditional Access policies that can block access for the administrator account. This requirement does not apply to the items or users being migrated in the project.

Configuring Modern Authentication to work with MigrationWiz is due to Microsoft discontinuing support for Basic Authentication in Exchange Online in October 2022. The following Microsoft documentation outlines this change in more detail. Should you have additional questions on how this change may impact your tenant, please contact Microsoft to assist with providing that information: Deprecation of Basic authentication in Exchange Online

The Azure Security Defaults must be disabled in the tenant. (This is often enabled by default for all new Exchange Online tenants and there is no workaround for this requirement). For steps on where to enable/disable the Azure Security Defaults, see Enabling security defaults in the following Microsoft documentation. To disable, set Enable Security defaults to No: Security defaults in Azure AD

Steps for enabling MigrationWiz to use Modern Authentication with Exchange Web Services in the tenant

Important: The option to add users to the project using Autodiscovery of source items will not work with Modern Authentication configured to be used with MigrationWiz. One of the other options for adding users to the project will need to be used with the steps outlined under Add Users later in this guide.

1. Log in to the Azure AD admin console with a Global Administrator login.
2. Select Azure Active Directory in the Azure Active Directory Admin Center.
3. Select App Registrations, which is found under Manage.
4. Select New Registration at the top of the screen.
5. Give the app a distinct name. You can change this later if necessary.
6. Select the Accounts in any organizational directory button.
7. Under Redirect Uri, select Public Client (mobile & desktop) and set it to urn:ietf:wg:oauth:2.0:oob
8. Click Register.
9. Go back to App registrations.
10. Select the App you just created.
11. In the Overview, you will find a ClientId (aka Application) and Directory (Tenant) ID.
12. Copy both of these to another application, such as Notepad, for use later in this process.
13. Under the Manage menu, select Authentication.
14. Set the option Allow public client flows to Yes. 
15. Click Save.
16. From the Manage menu, select API permissions.
17. Select Add a Permission.

18. Select APIs my organization uses

19. Scroll down and select Office 365 Exchange Online

20. Then select Delegated Permissions

21. Select EWS

22. Check the box under EWS for EWS.AccessAsUser.All.
23. Click Add permissions. This permission only allows the OAuth application (MigrationWiz) to be associated with EWS.
    1. • Important: This does not grant access to all mailbox data.
24. Click Grant admin consent.
25. Click Yes to confirm the settings.
26. In MigrationWiz, select the project that needs to be configured for Modern Authentication.
27. Click the Edit Project menu.
28. Select Advanced Options.
29. Under Support Options enter the ClientID and TenantID information you saved earlier in the following format:
    • If enabling Modern Authentication for the Source:
      • ModernAuthClientIdExport=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
      • ModernAuthTenantIdExport=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
    • If enabling Modern Authentication for the Destination:
      • ModernAuthClientIdImport=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
      • ModernAuthTenantIdImport=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx 
        • Enter the specific ClientID and TenantID for your tenant in place of the xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.
        • These options can be entered for either the Source or the Destination, or both, depending on the settings on the tenants.
        • These options need to be configured for each MigrationWiz project that needs to have Modern Authentication enabled.
          
          
30. Run a Verify Credentials to confirm that MigrationWiz can connect using Modern Authentication. 
31. Click on the item that was verified. There will be a message in the MigrationWiz Migration Information page that Modern Authentication is being used. This message will show in the “Migration Errors” box; however, it is not an error. This is just a message confirming that Modern Authentication is now active and being used for the connection.

This guide presumes that your Microsoft 365 tenant and users have already been created, and licenses have been assigned to enable the user mailboxes in Microsoft 365. If not, stop here and complete the Microsoft 365 setup as necessary, then continue with the following steps.

1. Confirm the destination administrator account has a Microsoft 365 license and an active mailbox.
2. Create the first Public Folder mailbox.
3. Run PowerShell commands

Create public folder mailbox

If you have not created the first Public Folder mailbox in the tenant, follow the steps below. The following steps need to be used to create the first public folder mailbox correctly (this will be the Primary Hierarchy mailbox) in order to use MigrationWiz for this project type. It would be best to have your MigrationWiz project already created for testing. Those steps can be found below.

Do not name the primary mailbox the same as any public folder mailbox
or database on the source On-Premise Exchange server.

 This step is required regardless of migration project size.

1. Log in to the Microsoft 365 portal as the user in the migration project. Make sure the user is an administrator. (You can easily tell, as there will be an Admin tab present in the upper right menu). If the user is not an admin, then assign the user the global admin role.
2. From the Admin tab, select Exchange. Click on the Public Folder option in the left panel. Click on the Public Folder Mailboxes topic in the top menu.
3. Create the first public folder mailbox (this will become the primary).
4. Once the first public folder mailbox is created, click on Public Folders and then ... . Add the destination administrator account being used in the project as Owner. If there is a box for applying the permissions to sub-folders, make sure it is checked before saving.
5. Create a test public folder in the administrator UI where you just added the permissions.
6. Set DefaultPublicFolderMailbox so that the destination administrator account mailbox being used is pointing at the newly created public folder mailbox in the destination tenant using the following PowerShell command:
   Set-Mailbox –Identity migrationwiz@domain.onmicrosoft.com –DefaultPublicFolderMailbox 365PFMBX


     Replace migrationwiz@domain.onmicrosoft.com with the destination admin account being used and 365PFMBX with the name of the public folder mailbox you just created.

7. If logged into Microsoft 365 with destination administrator account being used in project, then log out.
8. After 15-30 minutes, log back into Microsoft 365 with the destination admin account and open its OWA mailbox.
9. Attempt to add the test folder created in step 5 as a favorite in OWA. This is done by right clicking on Favorites or Folders.
10. If step 9 is successful, attempt to Verify Credentials in the public folder MigrationWiz project by selecting your line item and then select Verify Credentials from the Start Menu.
11. If the Verify Credentials pass fails, walk through the above steps again to ensure you did not miss a step. If it continues to fail, contact BitTitan Customer Support.

 You will need more than one public folder mailbox if migrating over 20 GB of data. See Large Migration Steps for more details.

PowerShell Commands

After all public folder mailboxes that are required for this migration have been created, you will want to increase the maximum send and receive limits, and increase the individual public folder size quotas for migration. Run the following PowerShell commands in the destination tenant:

Set-OrganizationConfig -DefaultPublicFolderProhibitPostQuota Unlimited -DefaultPublicFolderIssueWarningQuota Unlimited

Get-Mailbox -PublicFolder | Set-Mailbox -PublicFolder -MaxReceiveSize 150MB -MaxSendSize 150MB

The following steps will be performed in MigrationWiz.

1. Create project
2. Create endpoints
3. Add items
4. Run Verify Credentials
5. Purchase licenses
6. Set Advanced Options

Purchase licenses

Purchase Public Folder licenses. To obtain an estimate of the number of Public Folder migration licenses required for your migration project, follow the directions in Estimating the Required Public Folder Migration License Count.

Set Advanced Options

1. Under Source/Destination, set the value for Migrate Permissions For from New Folders Only to New folders and existing folders. This is required because Public Folder mapping scripts have been created. See Migrating Public Folder Permissions
2. Set value for Licensing/Maximum licenses to consume per item per pass licensing count. Default = 1. This allows up to 10GB to be migrated. Example: If migrating all Public Folders, using the forward slash ( / ), and the total data size = 78GB, then increase this value to 8 (otherwise the migration will pause at 10GB). See MigrationWiz Licenses.
3. Set your Preferred BitTitan Data Center. For the most optimum migration speeds, select the Data Center that is closest to your Microsoft 365 destination tenant. Refer to MigrationWiz - General - FAQ.

Under Support Options add:

• RemoveFilterBasedOnFolderType=1 This support option is required if Public Folders contain items other than mail, such as calendar and contact items. This option stays in place for the entire migration process.

You will now begin your migration. This will occur in multiple phases. Each migration pass has additional required advanced options and will be submitted as a Full Migration. Each pass must be completed successfully before moving on to the next migration pass.

1. First migration pass
2. Second migration pass
3. Security group permissions migration pass
4. Mail-enabled public folders