Public folder to Shared mailbox migration

Planning a Public folder migration to Microsoft 365

Before you migrate the Public folder to Shared mailboxes, you need to consider the migration requirements and prerequisites. Following is a checklist of items to identify and prepare your environments.

1. Back up your existing Public folder mailboxes and their contents.
2. Prepare a complete inventory of items from your source tenant.
3. Identify the size and number of Public folders you want to migrate
4. Note that the Shared mailboxes have a mailbox limit of 50GB. If you want to migrate large Public folders to the target, consider splitting the Public folders or reducing their size.
5. Determine whether you want to move everything at once or in stages
6. Check your internet connection speed and network configuration.
7. Identify the type of your current migration environment (Hybrid or non-Hybrid)
8. Consider the throttling and message size limits on Office 365
9. Communicate the plan and the changes to your end users.
10. Perform a test Office 365 migration before you start the actual one.
11. Start the migration, verify the endpoint and add DNS records.
12. Create new Outlook profiles and check if you are receiving mails correctly.

Pre migration activities for O365 Public folder migration

1. Ensure that you meet the network and bandwidth requirements for the migration. See network and migration planning, performance factors and best practices for Office 365 Public migration
2. Prepare your target Office 365 tenant. See tenant roadmap for Microsoft 365.
3. Before you migrate to Office 365, ensure that you create mailboxes for your users in your organization and assign suitable licenses to them.
   • Add users and assign licenses to Office 365 users
   • Assign Microsoft 365 licenses to user accounts
4. If you plan to migrate the source Public folders to Shared mailbox or another Public folder, ensure that you create and configure them on the target Office 365
   • Create Shared mailboxes on the target Office 365 tenant and set the correct permission
   • Create Office 365 Public folder and assign mailbox user
5. Assign the Organization Management role group in Exchange online to the admin user on both the source and the target. It is an elevated permission that is required to migrate Public folders.
6. Set the impersonation rights for the admin account in Office 365 to migrate mailboxes on behalf of other users in your organization.Verify if the source and target admin account in general has the following management roles assigned:
   • ApplicationImpersonation
   • View-Only Configuration
   • View-Only Recipients
   • Public Folders
   • User management administrator/Global administrator

    See how to set impersonation rights on Office 365 by using PowerShell cmdlets and from the Office 365 admin center.

7. Check if the Global admin account with the management roles has a valid and non-hidden mailbox on the source and target server.
8. If you have a custom email domain from your hosting provider to which you want to migrate and receive emails, you must add the custom domain and verify it on the target Office 365.
9. Configure Office 365 to send and receive large messages

    Follow the steps to increase the message size on Office 365 to 150MB.

   Note: For migrating Public folders to Office 365 with EdbMails, you do not require PowerShell scripts. The following steps describe the public migration method with EdbMails graphical user interface (GUI).

II. Migrate Office 365 Public folder to Shared mailbox

The following methods can help you to migrate Public folders to Shared mailboxes with EdbMails.

1. Direct migration of Public folder to Shared mailbox
2. Migrate to Office 365 with the PST import method

Steps to migrate Public folder to Office 365 Shared mailbox

• Step 1: Download and install EdbMails Office 365 migration software
  • Download EdbMails and install the application on any computer that is connected to the source and target environment. You can also perform the migration operation by installing EdbMails on a non-Exchange server computer.

     See a detailed list of EdbMails system requirements for Office 365 migration.

    

  • Launch the application and click ‘Login’ or ‘Start Your Free Trial’

    

  • Select the migration technique as Office 365 migration

    

    Note: If the Standard folders (such as Inbox, Calendar, Contacts) on your source server mailboxes are initialized with a different language, follow the details to migrate these folders to the respective system folders on the target (destination) server.

    For Instance: If your source Inbox folder is named 'Boîte de réception', which is in French language and you migrate this folder directly to the destination server, then by default it will not be mapped to the 'Inbox' folder on the target server. In order to map the folder with the french name to the respective folder, change the regional settings on the target server to match that of your source mailbox folder language (in this case, it is French).

     Steps to change the language and regional settings on Office 365

• Step 2: Connect to the source Office 365 as Global Administrator

  In the Connect to Office 365 (Source) window, select the authentication method as Auto or Manual registration for modern authentication and the connection method as Public folder. Enter the global administrator credentials to authenticate. 

   Connect to Office 365 server using secure modern authentication

  

  After you authenticate and log in successfully, select one of the methods to load the mailboxes. You can also load and migrate the mailboxes using a CSV file. See the steps if you want to exclude a public folder from migration.

  

• Step 3: Select the Public folder and connect to Office 365
  • Select the public folders that you want to migrate
  • Click ‘Migrate to Office 365’ to set up the connection with the target server.

    

     Tip: If this is the first time you’re migrating with EdbMails, the migration is a full migration. On subsequent migrations from the same source to the target, the migration is incremental.

    EdbMails provides the following additional options to help you customize the migration task.

    1. Additional Include and Exclude Filter Options
    2. Filter emails by Date: Migrate to Office 365 by applying the Date filter
    3. Filter emails by Size: Exclude emails or attachments larger than a specified size.

    

• Step 4: Connect to target Office 365 as Global Admin User

  EdbMails supports both modern and classic authentication. Connect to the target server by selecting Auto or Manual registration for modern authentication and the connection method as Mailboxes if you want to migrate to a Shared mailbox. 

   Connect to Office 365 server using secure modern authentication

  With EdbMails, you have the following migration choices:

  • Migrate the source Public folder to Shared mailboxes
  • Migrate the source Public folder to target Public folder.
  • Migrate the source Public folder to target mailboxes
• Step 5: Map the folders between the source and the target

  The mapping activity in EdbMails can automatically match and map the mailboxes and folders between the two Office 365 tenants and saves time when you’re migrating a large number of public folders

  

   Tip: Click here if you would like to know the steps to set up Office 365 email signatures for Shared mailbox.

• Step 6: Start the Public folder migration to Office 365

  Start and monitor the migration operation after you complete the mapping. Finally, verify the count of migrated emails, folders and mailbox items with EdbMails text-based log report.

Office 365 Public folder migration by using PST import

If you have an exported PST file of the Public folder, you can also use EdbMails PST to Office 365 migration tool to import all your mail items into the cloud. The following steps outline the migration operation.

• Step 1: Select the migration method as Office 365 migration

  Download and run EdbMails if you haven’t installed it on your system. On the EdbMails migration selection popup, select the migration technique as Office 365 migration.

• Step 2: Add PST files in bulk to migrate to Office 365

  To add the PST files, close the Connect to Office 365 (Source) connection window and click migrate ‘PST to Office 365’ at the bottom. Add the required PST files and continue.

  

• Step 3: Connect to target Office 365 as Global Admin User

  EdbMails supports both modern and classic authentication. Connect to the target server by selecting Auto or Manual registration for modern authentication and the connection method as Mailboxes.

  Connect to Office 365 server using secure modern authentication

  

• Step 4: Map and migrate Public folder to the Shared mailbox

  The mapping activity in EdbMails can automatically match and map the mailboxes and folders from the PST file to Office 365. This activity saves time when you’re migrating a large number of Public folders. After you complete the migration, verify the count of the migrated items and folders with the help of EdbMails log report. You can also log into your Office 365 tenant and verify the migrated folders and items. Learn how to import multiple PST into Office 365.

III. Office 365 migration troubleshooting

 See Office 365 migration troubleshooting guide and Public folder troubleshooting for possible solutions related to migration errors. For more information on EdbMails Office 365  migration, see frequently asked questions (FAQs)

 See solutions if you are not able to migrate Public folders due to insufficient permissions.

 Related Links

1. Video - Office 365 Public folder to Office 365 migration