There are two ways available to migrate from Exchange Server 2019 to Subscription Edition (SE) – legacy upgrade and in-place upgrade. In legacy upgrade, you need to install the Exchange Server SE on a new Windows Server alongside an existing Exchange 2019 Server. After that, you can gradually migrate mailboxes and other resources from Exchange 2019 to SE. Microsoft allows coexistence between Exchange 2019 and Exchange SE during the current RTM version and till early CU release. After SE CU 2, coexistence will not be supported. Performing in-place upgrade is similar to installing a CU – simply run Exchange SE setup on an Exchange 2019 server that has CU14/CU15 already installed.
We will discuss both these methods in this article. However, before beginning migration, you need to prepare well in advance. You can also keep an Exchange migration tool handy for swift and seamless migration of data.
How to Prepare for Migration from Exchange 2019 to Exchange Server Subscription Edition (SE)
To perform Exchange 2019 to SE migration, prepare Exchange environment by following the steps given below:
- Ensure Exchange 2019 has CU 14 or CU 15 Installed: The Exchange Server 2019 should be running the CU 14 or CU 15 to upgrade to Exchange SE. So, ensure that the latest CU is installed on your server. You can run the Get-ExchangeServer | Format-List Name, Edition, AdminDisplayVersion command to get information on the CU version.
- Take Backup of Exchange Databases, Active Directory, and Custom Configurations: It is highly recommended to take full backup of Exchange Server, including databases, Active Directory (AD), and custom configurations. This will come in handy if anything goes wrong.
- Ensure you have correct Windows Server Version installed: Exchange SE supports Windows Server 2019, 2022, and 2025. So, ensure that you have correct OS installed before migration.
- Plan Migration in a Maintenance Window: Plan migration in a maintenance window, preferably during weekends or public holidays. This can help in lowering downtime.
- Check System Requirements: Review official Exchange SE system requirements for supported operating systems, memory, CPU, disk, and network specifications. Ensure Exchange Server’s hardware is compatible with what Microsoft recommends.
- Ensure Admin Accounts are Assigned Required Roles and Permissions: To perform migration from Exchange 2019 to Exchange SE, you need to use admin accounts with certain roles and permissions. For instance, Enterprise Admins and Schema Admins group roles are required for running AD schema prep commands. Local administrator account is needed for executing Exchange SE’s Setup.exe. One also needs to be a member of Organization Management group for migrating mailboxes from Exchange 2019 to Exchange SE.
Methods to Migrate from Exchange Server 2019 to Exchange Subscription Edition (SE)
Below we will be discussing in-place upgrade and legacy upgrade methods for migrating from Exchange 2019 to Exchange SE.
1. In-place Upgrade
In-place upgrade is a method of installing Exchange Server SE directly over existing Exchange Server 2019 (CU14 and later) installation on the same hardware. The in-place upgrade process is similar to applying a Cumulative Update on an Exchange Server. Here’s how to perform this upgrade:
- Download Exchange Server SE
Go to this link and download Exchange Server SE.
- Perform In-Place Upgrade from Exchange 2019 to Exchange Server SE
To perform in-place upgrade, find Setup.exe in downloaded files. After that, run the setup and follow the instructions on the screen. As installing Exchange SE is like installing a CU, you can use instructions in this link.
2. Legacy Upgrade
In legacy upgrade, you need to deploy new Exchange SE server alongside existing 2019 server, migrate mailboxes, and then decommission the old server after completing the transition. However, you can only use legacy upgrade method before Microsoft releases Exchange SE CU2. Below are steps to perform legacy upgrade:
- Prepare Active Directory Schema and Domains
Update Active Directory (AD) schema, configuration containers, and domain-level permissions by following steps in this link on any domain-joined computer.
- Add a Windows Server to the AD Domain of Exchange 2019
Install Windows Server (2019, 2022, or 2025) on a computer and add it to Active Directory domain of Exchange Server 2019.
- Download and Install Exchange Server SE
Download Exchange Server SE from Microsoft’s website. Install it on the new Windows Server by running Setup Wizard.
- Configure Certificates and Mail Connectors
Install and assign valid SSL/TLS certificates for Exchange services, like Outlook on the web, Autodiscover, and SMTP on Exchange SE. Next, build/update send and receive connectors.
- Move Mailboxes from Exchange 2019 to Subscription Edition
Use New-MoveRequest command in Exchange Management Shell (EMS) to migrate mailboxes from Exchange Server 2019 to Exchange SE. Monitor mailbox move requests using cmdlets, like Get-MoveRequest and Get-MigrationUserStatistics. If you want to avoid using complex PowerShell scripting for migration and monitoring, use an Exchange migration tool.
- Update DNS Records and Connectors
Update MX, Autodiscover records, so that new emails arrive on new Exchange SE. Also, reconfigure anti-spam systems or connectors used for any third-party gateways to ensure mails are received on new Exchange SE.
- Uninstall Exchange Server 2019 and Clean up AD
After successful migration, validate mail flow and mailbox access on SE. If everything is fine, uninstall Exchange 2019 from older server. After uninstallation, remove any remaining Exchange objects such as servers and connectors from AD.
How to Verify Exchange Functionality after Exchange 2019 to SE Migration?
To verify Exchange functionality after Exchange 2019 to SE migration, run these checks:
- Confirm users have access to mailboxes, calendars, and shared resources.
- Check Exchange databases are healthy, mounted, and accessible.
- Test incoming and outgoing email flow from external/internal senders.
- Confirm services like OWA/Autodiscover are working properly.
- Check all critical Exchange services are running without errors.
- Review Event Logs for any warnings, errors, or services failure.
Challenges during Migration when using Above Native Methods
Here are some challenges you may face during Exchange 2019 to Exchange SE migration when using the native methods:
- Unforeseen Human Errors
PowerShell scripting is complex and requires technical expertise. Therefore, there are high chances of committing syntactical errors when executing the PowerShell scripts.
- Migrating Public Folder is a Bit Complex
Moving public folders is a bit complex than migrating mailboxes. The public folder migration process requires significant administrative efforts and time as it involves complex multi-step PowerShell scripting.
- Additional Administrative Effort Required to Monitor Migration Process
You need to run PowerShell commands, such as Get-MoveRequestStatistics and Get-MailboxStatistics to check the migration progress. However, frequently running these commands requires a lot of administrative effort.
How to Simplify Exchange 2019 to Exchange SE Data Migration?
You can use a specialized Exchange migration tool, like Stellar Migrator for Exchange, to effortlessly migrate mailboxes, user archives, and public folders from Exchange Server 2019 to Exchange SE. This tool significantly reduces admin efforts and saves time. You just need to connect the source server (Exchange 2019) and the target server (Exchange SE) using admin credentials, map the mailboxes, and start the migration. This Exchange migration tool supports both same and cross domain migrations. In addition to Exchange to Exchange migration, Stellar Migrator for Exchange supports Exchange to Microsoft 365 migration and vice-versa.
Here are some benefits of using this Exchange migration tool:
- Eliminates Human Errors: The tool’s intuitive GUI wizard and dashboards help migrate the data in a few simple clicks, thus eliminating the chances of human errors.
- Easily Migrates Public Folders: Migrates Public folders while preserving folder hierarchy without multi-step scripting.
- Shows Real-Time Migration Progress: The tool shows real-time migration progress and provides detailed summaries and reports on migration progress.
Conclusion
In-place upgrade and legacy upgrade are two native methods to migrate Exchange from 2019 to Subscription Edition (SE). Above, we have explained these methods in detail. However, when it comes to migration of data, you can use Stellar Migrator for Exchange – a specialized Exchange migration tool. It enables migration of mailboxes, archives, and public folders across Exchange Servers and Microsoft 365 via a simple user-friendly interface. It has informative dashboards and live progress tracking features that allow users to monitor migration progress in real-time.
