Office 365 to Exchange 2019 migration

1. Evaluate your current Office 365 environment

   Before you begin the migration process, evaluate your current Office 365 environment, including an inventory of users, email domains, distribution lists, and custom configurations. Identify potential issues such as throttling and ensure you meet the bandwidth and network requirements for the migration.

2. Prepare your Exchange 2019 environment

   Prepare your Exchange 2019 environment by setting up the necessary infrastructure such as the Active Directory domain and Exchange Server. Configure custom settings or policies that you had in your Office 365 environment.

3. Configure Exchange 2019 for Hybrid Deployment

   Configure Exchange 2019 for hybrid deployment, which allows you to have a seamless migration between your Office 365 environment and your on-premises Exchange server. The hybrid deployment configuration involves setting up the Exchange hybrid agent, configuring the Exchange Online Connector, and setting up your hybrid mail flow.

4. Plan the Exchange to O365 migration

   Plan the migration carefully to avoid any data loss or downtime. Decide the order in which you'll migrate your mailboxes and data, how to migrate them, and how to keep track of the progress.

5. Test and perform a pilot migration

   Before migrating any mailboxes, verify that the Exchange 2019 environment is working correctly. Test the mail flow, mailbox access, URL and custom configurations or policies.

6. Migrate mailboxes and data to Exchange 2019 

   After testing the Exchange 2019 environment, start migrating mailboxes and data from Office 365 to Exchange 2019. You can use EdbMails for transferring the mailboxes. 

7. Verify and test the migration 

   After you have completed the mailbox migration, verify and test the migration to ensure that everything is working correctly. Test mail flow, mailbox access, and custom configurations or policies. Configure Outlook profile for the users in your organization and ask them to change the password. 

8. Decommission Office 365 and remove any licenses

   After verifying and testing the migration, decommission your Office 365 environment. Remove any Office 365 licenses, delete your Office 365 tenant, and disable any remaining Exchange Online connectors.

Before you begin the migration process, ensure that the source and destination Exchange environments are ready. It's also important to evaluate your current Office 365 environment, which may include taking an inventory of your users, email domains, distribution lists, and any custom configurations. You'll also want to identify any potential issues or roadblocks that could arise during the migration process.

• Step 1: Check that you meet the following requirements on Office 365
  1. Decide the migration path you want to take depending on your environment.

     Current environment and requirement	Migration approach	How does the migration take place?
     You want to migrate mailboxes from O365 to on-premise Exchange 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 migrate from Office 365 to Exchange 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 from Office 365 to Exchange on-premises coexisting in a hybrid environment.

  2. 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.
  3. 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.
  4. 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
  5. Check if the Global admin account with the management roles has a valid and non-hidden mailbox on the source and target server.
• Step 2: Check that your system meets the Exchange server setup requirements

  After you've evaluated your current Office 365 environment, it's time to prepare your Exchange 2019 environment. This task includes setting up the necessary infrastructure, such as the Active Directory domain and the Exchange Server itself. You'll also want to configure any custom settings or policies that you had in your Office 365 environment.

  The following links will help you set up your target Exchange 2019 environment Learn more about the network, hardware and operating system requirements for installing Exchange 2019 server.

  1. Network and directory requirement for Exchange 2019
  2. Hardware Requirements for Exchange 2019
  3. 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
• 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.

  Note: If you have already installed and set up Exchange 2019, skip to point 4 in this section.

  1. Prepare 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.
  2. 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.

  3. 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).
  4. Create mailboxes and Public folders on the Exchange server

     Ensure that you create mailboxes on the target Exchange server and assign suitable licenses to them. Similarly, create Public folders if you are planning Public folder migration from Office 365 to Exchange.

     1. See how to create mailboxes in Exchange server
     2. Steps to create Public folder in Exchange server
  5. Assign management roles to the admin account

     Set the following permissions to the admin account on the Exchange server.

     1. ApplicationImpersonation
     2. View-Only Recipients
     3. View-Only Configuration
  6. 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.

  7. 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

You can migrate Office 365 to Exchange 2019 with the following methods

• Method 1: Office 365 to Exchange 2019 cutover migration
• Method 2: Batch or Staged migrate from O365 to on-premise
• Method 3: Hybrid migration between Office 365 and Exchange
• Method 4: Migrate Office 365 to Exchange 2019 with PST files

• Method 1: Steps for Office 365 to Exchange migration (cutover)
  • Step 1: Download and install EdbMails migration tool for Office 365
    • Download EdbMails Office 365 migration tool and install the application on the source computer.
    • The application is compatible with all Windows Server and Windows operating systems.

       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, and Contacts) on the source Office 365 mailboxes are set to a different language, follow the instructions to migrate these folders to the appropriate system folders on the target (destination) server.

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

       Steps to change the language and regional settings in Exchange

  • Step 2: Connect to Office 365 with Global Admin credentials

    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 your 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 mailboxes and folders to migrate to Exchange 2019
    • EdbMails displays a list of mailboxes from the source Office 365 tenant.

       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.

    • Select the mailboxes and folders that you want to migrate.
    • Click ‘Migrate to Live Exchange’ to set up the connection with the target server. If you are looking to backup your mailbox data, you can also export Office 365 mailboxes to PST with EdbMails.

      

  • Step 4: Connect to Exchange server 2019 with Global Admin credentials

    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.

    

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

    

  • Step 5 : Migrate Office 365 to Exchange 2019 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.

• Method 2: Steps for Microsoft 365 to Exchange staged migration

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

  • Step 1: Install EdbMails and log in to the 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 Office 365 mailboxes to migrate to 2019 Exchange
    • After a successful login, EdbMails displays a list of mailboxes and folders.
    • Select the mail objects you want to migrate and click ‘Migrate to Live Exchange’
  • Step 3: Prepare your data for staged migration to Exchange 2019

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

    1. Additional Include and Exclude Filter Options
    2. Filter emails by Date: Migrate to Exchange by applying the Date filter
    3. Filter emails by Size: Exclude emails from migration larger than a specified size.
    4. Filter emails by Domain: Migrate emails Exchange based on the email domain.

    

  • Step 4: Connect to Exchange 2019 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: Perform mailbox mapping and start the Exchange staged 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.

     Tip: You can repeat these steps if you want to transfer another batch of mailboxes to the target.

• Method 3: Migrate Office 365 to Exchange by using Hybrid migration

  If you plan to migrate mailboxes within an on-premises Exchange and Office 365 environment, then a Hybrid migration is the best solution.

   See Office 365 Hybrid migration planning guide with EdbMails for steps to perform Hybrid migration.

  If your mailboxes are in a Hybrid environment, you cannot migrate Public folders directly from Office 365 because they cannot simultaneously coexist on the cloud and on-premises. See a workaround solution to migrate Public folders in a hybrid environment.

• Method 4: Office 365 to Exchange 2019 migration with PST files

  If you have exported Office 365 mailboxes as PST files, EdbMails can help you to migrate mailboxes from O365 to Exchange 2019 by using the PST files.

  • Step 1: Install EdbMails and select Exchange migration
    • Download and install EdbMails application on your computer
    • Select the option ‘Live Exchange Migration (Hosted, hybrid, on-premise and more..)’ from the main screen.

      

  • Step 2: Select multiple PST files to migrate to Exchange 2019
    • Now, close the Exchange server source connection window, and select ‘Migrate PST to Live Exchange’ as shown.
    • Select and add the PST files in bulk to migrate to the Exchange server.

      

      

  • Step 3: Connect to Exchange server 2019 as Global Administrator
    • After adding the PST files, connect to the target Exchange 2019 server with the global administrator credentials.
    • Map the source mailboxes to the respective target mailboxes.
  • Step 4: Migrate the PST files from Office 365 to Exchange 2019
    • Start the mailbox migration to the Exchange server from the PST files.
    • EdbMails displays a progress window where you can also pause and resume the migration.
    • Finally, verify the migrated items and folders with the log-report and also by logging into your Exchange 2019 server.

The following steps apply only if you no longer wish to use Office 365 and want to switch back to on-premises Exchange permanently.

• Step 1: Update the MX records to point to the Exchange server

  To receive messages on Exchange, change the DNS records known as MX records to enable email to work with the new server you have migrated to. In addition, configure the Autodiscover record to allow Outlook to connect to the migrated mailboxes.

• Step 2: Create a new Outlook profile for users in the new domain
  • Ensure you have the latest version of Outlook installed to avoid compatibility issues.
  • Configure the Outlook profile for each user in your domain if Outlook has problems connecting to Office 365 mailboxes.
  • Configure the new server settings, such as the server address, username, and password in Outlook.
  • Test email flow to ensure that your users are able to send and receive emails.
• Step 3: Remove the old Office 365 subscription plan

  After the migration is successful and you have verified the data, remove the Office 365 subscription plan from the source and any domains associated if you no longer plan to use it.