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Read time 6 minutes

Summary: Migrating from Exchange to Office 365 involves various methods, including CSV batch creation. This article emphasizes the importance of Office 365 Groups for collaboration, especially when migrating public folders. It provides a manual process for migrating public folders to Office 365 Groups, including script downloads and steps. The article highlights important considerations and limitations for this migration method and suggests using Kernel Migration for Exchange for a streamlined and error-free process.

Migrating to Office 365 from Exchange is a complex undertaking, and Microsoft offers a range of migration methods, including cutover, staged, and hybrid migration. These methods cater to different Exchange versions and come with varying mailbox migration limits. However, a common step among these methods is the need to create migration batches using CSV files. Users must configure a CSV file and initiate a new batch to kickstart the migration process. In this article, we will guide you on seamlessly migrating Public folders from your Exchange account to an Office 365 Group directly, simplifying this critical task.

What do Office 365 groups perform in the account?

Office 365 Groups provide a cohesive platform for consolidating multiple Office 365 accounts, facilitating seamless communication, information sharing, and routine correspondence. They significantly enhance collaborative efforts among users, teams, and clients, fostering increased synergy. Whether you are engaged in a special project that demands sharing documents, spreadsheets, project plans, and more with your team members, creating Office 365 Groups is a recommended solution.

Public folders serve a valuable role in facilitating data sharing. Consequently, Office 365 groups emerge as the logical choice for housing such data. However, it’s crucial to emphasize the importance of assessing your organization’s specific requirements before establishing an Office 365 group. A one-size-fits-all approach doesn’t apply here, as diverse teams seek varying levels of collaboration. Therefore, it becomes imperative to create distinct groups tailored to different applications and teams’ unique collaborative needs.

  • When you want to do some extensive email communication and also share the calendar, then create the Office 365 group in Outlook.
  • When do not require the high level of sharing, but the continuous chats for the instant communication, then create the Office 365 group in Microsoft teams.
  • When you require some large-scale discussions where a great number of users can share their idea like a forum panel, then create the Office 365 groups in the Yammer.

When migrating public folders from Exchange to Office 365, there isn’t a straightforward, direct method available. However, you can accomplish this task by utilizing the Exchange Management Shell. If your goal is to migrate the public folder mailbox to Office 365 exclusively, you can proceed directly, treating it like any other mailbox without making extensive alterations. However, if you’re looking to replace legacy public folders with Office 365 groups, the following procedure outlines the steps to follow.

Manual Process to Migrate Public Folder to Office 365 Groups

The manual process to migrate the public folders is completed in multiple steps, and here we have provided the steps here:

  1. Download the migration scripts from the following URL:


    There are multiple scripts which are essential in the migration process at multiple levels –

    A. AddMembersToGroups.ps1
    It helps to include the users and owners from the source Exchange.

    B. AddMembersToGroups.strings.psd1
    It is an associate script for the first script.

    C. LockAndSavePublicFolderProperties.ps1
    It locks the public folder from any updates or changes while migration is in progress.

    D. LockAndSavePublicFolderProperties.strings.psd1
    It is an associate script for the third script.

    E. UnlockAndRestorePublicFolderProperties.ps1
    It unlocks the public folder’s properties and restores them to their original state.

    F. UnlockAndRestorePublicFolderProperties.strings.psd1
    It is associated script for the fifth script.

    G. WriteLog.ps1
    It activates the first, third, and fifth scripts to write logs.

  2. Prepare the migration environment: Perform the steps to create a suitable migration environment –
    1. List all the public folder content which you want to migrate.
    2. Prepare a list of Office 365 Groups and map them with source public folders. Create new Groups if required.
    3. Make sure that public folders do not have a name containing a backslash (\). The MoveRequest command will not migrate such public folders.
    4. There is a unique PAW feature which should be in enabled state in the Office 365. You can check the status of this feature using the following command –


    It will provide you with a list of all the features in Office 365. If the record has PAW in it, it means it is enabled.

  3. Create a comma separated value (.csv) file: Create a CSV file having two columns FolderPath and TargetGroupMailbox. The FolderPath will include the complete path of the public folder and TargetGroupMailbox will have the Office 365 Group SMTP address. You also should know that you can create only 500 entries in a single CSV file.
  4. Start the Batch Migration: Before starting the batch migration, you should complete some prerequisites –
    1. Find the MRS Proxy Endpoint for Exchange 2016 and 2019.
    2. Go to Exchange Online (Office 365) Powershell and run following commands –

    Provide the administrator credential (of the source Exchange Server) to $Source_Credential variable –

    $Source_Credential = Get-Credential

    Provide the MRS Proxy Endpoint to the $Source_RemoteServer variable –

    $Source_RemoteServer = “MRS Proxy Endpoint”

    Create the migration endpoint with the following command –

    $PfEndpoint = New-MigrationEndpoint -PublicFolderToUnifiedGroup -Name
    PFToGroupEndpoint -RemoteServer $Source_RemoteServer -Credentials $Source_Credential

    Create a new migration batch –

    New-MigrationBatch -Name PublicFolderToGroupMigration – CSVData (Get-Content <path to .csv file> -Encoding Byte)
    -PublicFolderToUnifiedGroup -SourceEndpoint $PfEndpoint.Identity [-NotificationEmails
    <email addresses for migration notifications>] [-AutoStart]

    As you have added the AutoStart parameter, the migration will instantly start.

  5. After completing the batch migration, you can delete the batch migration request with the following command:
    Remove-MigrationBatch “name of migration batch”

    So, this is the whole process of migrating public folders from on-premises Exchange to Office 365. But there are lots of patchworks which you need to fix before and after the process. Here are some conditions which the batch migration process should fulfill –

    1. The migration supports only emails and calendar items of the public folder. It does not support the migration of other elements of the public folder.
    2. If the public folders have sub public folder, then they will not be migrated. You need to migrate them in a separate batch manually.
    3. The method is feasible for only Exchange Server CU14 and later versions.
    4. An Office 365 group can contain data up to 50 GB. So, make sure that a batch is not migrating data more than 50 GB.
    5. You can run only one public folder migration batch at a time. If you create another batch and run it, then it will show error and might corrupt the data.
    6. You need to run lock-down scripts to lock the public folder data. This way the users will be prompted to use Office 365 group rather than the public folder.

Final Words

Migrating public folder data to Office 365 can be a challenging and time-intensive task, often prone to errors that demand a high level of expertise. If you’re seeking a solution to streamline your migration process and minimize potential issues, consider utilizing Kernel Migration for Exchange. This powerful tool facilitates direct access to public folders at their source and seamlessly relocates them to your preferred Office 365 Groups. With its array of advanced filtering options, you can effortlessly cherry-pick the specific data you wish to migrate using Exchange Migration tool.