Cross-forest Exchange server migration

1. Pre Migration Tasks

   Before you migrate to the target server, you need to create a valid mail-enabled user in the target forest with a specified set of Active Directory (AD) attributes. The following table illustrates the coexistence scenarios in various Exchange server versions.

   Exchange server version	Coexistence scenario	Requirement	Migration
   Exchange 2019	Possible. Can coexist with Exchange 2013 Can coexist with Exchange 2016	Install Cumulative Update 21 (CU21) or later on Exchange 2013 Install Cumulative Update 11 (CU11) or later on Exchange 2016	With EdbMails Exchange migration software, you can migrate to any Exchange server version regardless of the coexistence issue
   Exchange 2016	Possible. Can coexist with Exchange 2013 Can coexist with Exchange 2010	Install Cumulative Update 10 (CU10) or later on Exchange 2013 Install the latest Rollup update for Exchange 2010 Service Pack (SP3)

   If you have deployed the Identity Lifecycle Manager (ILM) to synchronize the cross-forest global address list (GAL), ensure that you use the Microsoft Identity Manager 2016 SP1 and use the following code in the link to synchronize the source and target mailbox user.

   If you have created the target mailbox user by using an Active Directory tool, run the Update-Recipient cmdlet to generate the LegacyExchangeDN. The following link outlines the procedure to create the target user by using PowerShell script.

2. Cross-forest migration from Exchange 2013 to Exchange 2019/2016 using EdbMails

   Steps to perform cross-forest migration

   • Step 1: Download and install EdbMails Exchange server migration software setup
     1. Download EdbMails and install the application on the source Exchange server or any other computer. You can also perform the migration operation by installing EdbMails on a non-Exchange server computer.
     2. Launch the application and click 'Login' or 'Start Your Free Trial'.

     

      Refer to the link for a detailed list of EdbMails system requirements for Exchange migration.

     Note: If the Standard folders (such as Inbox, Calendar, Contacts) on your source Exchange server mailboxes are initialized with a different language, follow the below 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).

      Click here to know the steps to change the language and regional settings on Exchange server

   • Step 2: Select the appropriate migration technique

     Select 'Live Exchange Migration' for cross-forest migration and proceed to the following step to grant the Global administrator account the necessary permissions.

     

   • Step 3: Set the impersonation rights for the Global Admin

     Login as a global admin if you are migrating mailboxes on behalf of other users in your organization. If you do not have the necessary permissions, set the impersonation rights for the admin user account on the source Exchange server.

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

     In the Connect to Exchange server (Source) window, select 'Connect using Global Admin User'. Refer to the link for 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 the source Exchange to the target server.

   • Step 5: Select the mailboxes and connect to the target Exchange
     1. Select the mailboxes and folders from the source Exchange server that you wish to migrate to the target server.
     2. Click 'Migrate to Live Exchange' to setup the connection with the target server

     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.

     

   • Step 6: Customize the migration operation

     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 target Exchange by applying the Date filter
     3. Filter emails by Size: Exclude emails from migration larger than a specified size.

     

   • Step 7: Connect to target Exchange server as Global Admin User

     Connect to the target server by selecting the option 'Connect using Global Admin User' and the migration scenario as Mailboxes, Public folder or Archive Mailbox.

     

   • Step 8: 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 two Exchange servers and saves time when you migrate a large number of mailboxes.

     

   • Step 9: Start the migration to the target Exchange

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

     

3. Post Migration Tasks

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

     To receive messages on the Exchange server 2019 to 2016, 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

     Configure the Outlook profile for each user in your domain if Outlook has problems connecting to the new Exchange server.

   • Step 3: Decommission and uninstall the source Exchange server

     After the migration to the target Exchange server is complete, decommission or uninstall the source server, depending on which Exchange server you used as the source.

      Steps to decommission Exchange server 2010

      Steps to decommission Exchange server 2013

Exchange migration troubleshooting

 Refer to the Exchange migration troubleshooting guide for possible solutions related to migration errors. For more information on EdbMails Exchange migration refer to the frequently asked questions (FAQs)

 See the prerequisites and migration steps if you want to migrate from Hosted Exchange to Exchange 2019 and 2016.