Office 365 to Exchange migration

1. Prepare a complete inventory of items that you want to migrate from Office 365.
2. Take a complete backup of all your mailbox items and folders and remove the unused and unwanted mailboxes from the source.
3. Determine if you want to follow the cutover migration, staged or hybrid migration method.
4. Determine if you want to migrate Public folders and Shared mailboxes to the target along with the primary mailbox.
5. Determine the size of the mailbox data and number of mailboxes to migrate.
6. Communicate any changes to your end users and inform the stakeholders.
7. Prepare the domains and required Active Directory services on the target.
8. Create mailboxes and Public folders on the target Exchange server
9. Assign suitable licenses to the mailboxes.
10. Ensure you have enough network capacity and bandwidth to migrate.
11. Consider the throttling and message size limits on the Exchange server.
12. Perform a test (pilot) migration before you start the actual one.
13. Start the migration, verify the endpoint and add the DNS records.
14. Create new Outlook profiles for the users and check if you are receiving mails correctly.
15. Remove the permissions and licenses on the source Office 365 tenant.

I. Pre migration activities for Office 365 to Exchange migration

• Step 1: Check that you meet the following requirements on Office 365
  1. Assign the Organization Management role group in Exchange online to the admin user. It is an elevated permission that is required to migrate Public folders.
  2. 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:
     1. ApplicationImpersonation
     2. View-Only Configuration
     3. View-Only Recipients
     4. Public Folders
     5. User management administrator/Global administrator
  3. Check if the Global admin account with the management roles has a valid and non-hidden mailbox on the source and target server.
  4. 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 migration.
  5. Decide the migration path you want to take depending on your environment.

  Current environment and migration requirement	Migration approach	How does the migration take place?
  You want to perform a complete migration to the Exchange server in a single event and in a limited time frame.	Cutover migration	In this approach, you set up your target Exchange server and migrate everything in a single sitting. Suited for large mailbox migration
  You want to perform the migration in phases	Staged migration	In this approach, you migrate your mailboxes and mail data in stages and transfer the required or the most recent data first followed by the others.
  You want to migrate your Office 365 cloud data to an on-premises Exchange server that exists in a hybrid environment.	Hybrid migration	In this approach, you migrate back to the on-premises Exchange server from Office 365 coexisting in a hybrid environment.

• Step 2: Check that your system meets the Exchange server setup requirements.

  The following links will help you set up your target Exchange server environment based on the Exchange version you want to migrate to. Learn more about the network, hardware and operating system requirements for installing Exchange server.

  Note: Exchange 2010 has reached the end of support on October 13, 2020 and Exchange 2013 will reach the end of support on April 11, 2023. Therefore it is highly recommended that you migrate your mail data and Public folders to Exchange 2016 or 2019.

  1. Exchange 2013 Server setup
  2. Network and directory requirement for Exchange 2016
  3. Network and directory requirement for Exchange 2019
  4. Hardware Requirements for Exchange 2016
  5. Hardware Requirements for Exchange 2019
  6. Supported operating systems for Exchange 2016
  7. Supported operating systems for Exchange 2019
• Step 3: Prepare your target system with the following prerequisites

  Complete the following prerequisites for Active Directory, Windows Mailbox server, and Windows Edge Transport servers before installing the Exchange server.

  1. Exchange 2019 prerequisites for preparing Active Directory (AD)
  2. Windows Server prerequisites for Exchange 2019
  3. Exchange 2016 prerequisites for preparing Active Directory (AD)
  4. Windows Server prerequisites for Exchange 2016
• Step 4: Set up Exchange Server for migration

  Given below is a list of key points for installing and preparing the Exchange server for migration.

  • Prepare the AD and domains
    1. Before installing Exchange Server, you need to prepare your Active Directory forest and its domains for the new version of Exchange.
    2. If you have a separate team to manage the Active Directory schema, you need to first extend the active directory schema, else proceed to the next step to prepare the Active Directory.
    3. If you have multiple domains you need to additionally prepare the Active Directory domains.
  • Install Exchange server on your computer

    Before installing the Exchange server, ensure that you meet the server system requirements and prerequisites as outlined previously. Next, follow the link to install Exchange 2016 or install Exchange 2019 from the setup wizard.

  • Prepare a clean Exchange target environment
    1. Create and configure a Send connector to send mail outside the Exchange organization.
    2. By default, Exchange automatically creates receive connectors for inbound mail flow when the mailbox server is installed. If you need to configure receive connectors, follow the steps in the link.
    3. Add accepted domains to allow recipients to send and receive email from another domain.
    4. Configure the default email address policy to add the accepted domain to every recipient in the organization.
    5. Configure external URLs (domains) on the virtual directories in the Client Access (frontend) services on the Mailbox server to allow clients to connect to your server from the internet (outside the organization’s network).
    6. Configure internal URLs on the virtual directories in the Client Access (frontend) services on the Mailbox server to allow clients to connect to your server from the internal network.
    7. Configure SSL certificates from a third-party certificate authority for services such as Outlook Anywhere and Exchange ActiveSync.
    8. Verify the Exchange server installation by running the command Get-ExchangeServer on the Exchange Management Shell (EMS)
  • Create mailboxes and Public folders on the Exchange server

    Before you migrate, ensure that you create mailboxes on the target Exchange server and assign suitable licenses to them.

     See how to create mailboxes in Exchange server

     Steps to create Public folder in Exchange server

  • Assign management roles to the admin account
    1. ApplicationImpersonation
    2. View-Only Recipients
    3. View-Only Configuration
  • Verify the mailbox of the admin account

    Check to see if the admin account that has been assigned management roles has a valid and non-hidden mailbox on the Exchange server.

  • Configure the throttling and message-size limits

    You can manually change the EWS throttling and message size limits on the Exchange server by following the steps in the link.

    1. Change the EWS throttling settings on Exchange server
    2. Change message size limits on Exchange

II. How to perform Office 365 to Exchange migration?

There are three methods to migrate to an on-premises Exchange server from the cloud.

1. Office 365 to Exchange cutover migration
2. Batch or Staged migration
3. Hybrid migration between Office 365 and Exchange

Steps for Office 365 to Exchange cutover migration

• Step 1: Download and install EdbMails Office 365 migration software

  • Download EdbMails and install the application on the source computer. You can also perform the migration operation by installing EdbMails on any 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 the source Office 365 mailboxes are initialized with a different language, follow the details in the link 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).

   Click here to know the 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 Mailboxes, Public folder or Archive Mailbox. 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.

• Step 3: Select the mailbox items and then connect to Exchange server
  1. EdbMails displays a list of mailboxes from the source Office 365 tenant.
  2. Select the mailboxes and folders that you want to migrate.
  3. Click 'Migrate to Live Exchange' 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 Exchange server as Global Admin User

  In the Connect to Exchange server (Destination) window, select 'Connect using Global Admin User' if you want to migrate mailboxes on behalf of all users. You can also connect to the mailboxes by loading a CSV file. See the instructions on how to use the different Exchange server connection methods supported by EdbMails.

   With EdbMails, you can migrate mailboxes, public folders, and archive mailboxes from Microsoft 365 to Exchange.

  

• Step 5: Map the mailboxes between the source and the target

  The mapping activity in EdbMails can automatically match and map the mailboxes and folders between the source tenant and target. This activity saves time when you’re migrating a large number of mailboxes.

  

• Step 6 : Migrate to Exchange from Office 365 and verify the endpoint

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

Microsoft 365 to Exchange staged migration

The staged migration with EdbMails involves migrating the newest emails and mail items to the Exchange server in the first stage and gradually migrating the remaining mailbox data in the subsequent stages or over weeks.

• Step 1: Install EdbMails and connect to the source Office 365 tenant

  Download and install the application and select Office 365 migration. In the connection page, select Auto Registration and connect to the source Office 365.

• Step 2: Select the mailboxes and folders to migrate to target Office 365
  1. After a successful login, EdbMails displays a list of mailboxes and folders.
  2. Select the mail objects you want to migrate and click 'Migrate to Live Exchange'
• Step 3: Prepare your mailbox data for Exchange staged migration

  EdbMails provides the following additional options to help you perform staged migration based on the Date and other conditions.

  1. Additional Include and Exclude Filter Options and migration settings for mailboxes.
  2. Filter emails by Date: Migrate to Exchange by applying the Date filter
  3. Filter emails by Size: Exclude emails or attachments larger than a specified size.

  

• Step 4: Connect to Exchange server as Global Admin User

  In the Connect to Exchange server (Destination) window, select 'Connect using Global Admin User'. You can also connect to the mailboxes by loading a CSV file. See the instructions on how to use the different Exchange server connection methods supported by EdbMails.

   With EdbMails, you can migrate mailboxes, public folders, and archive mailboxes from Microsoft 365 to Exchange.

• Step 5: Map the mailboxes and start the staged Office 365 migration

  The mapping activity in EdbMails can automatically match and map the mailboxes and folders between the source and target server. Start and monitor the migration and verify the count of migrated emails, folders and mailbox items with EdbMails text-based log report.

Benefits of EdbMails for Exchange online to Exchange migration

• Migrate Office 365 to Exchange server 2019, 2016, 2013 and 2010.
• Support for cutover, staged, hybrid and PST to Exchange migration methods.
• Zero downtime and zero data loss Exchange migration.
• You do not have to use PowerShell scripts and cmdlets for transferring your mailbox data.
• Migrate Public folder, In-Place Archive and Shared mailboxes in addition to the primary mailboxes.
• Highly secure migration with complete data consistency.
• EdbMails enables you to use your mailboxes even during the migration without affecting your data.
• Monitor and verify the migration with text-based log reports.
• Direct connection and automatic mailbox mapping between the source and target.
• World class expert 24x7 support to assist you with the migration.

 Related Links

1. Video - Office 365 to Exchange migration
2. Office 365 tenant to tenant migration
3. Export Office 365 mailboxes to PST