A configured and working Hybrid configuration must be in place between your source Exchange environment and the Microsoft 365 tenant for a successful migration. To ensure these prerequisites are met, we suggest working through the following checklist. Once each question can be answered with "Yes," proceed to the next step in the guide.
- Creation of Microsoft 365 tenant with domain (Namespace) configuration is completed.
- Azure AD Connect is set up and configured to include all Organizational Units where Mailbox accounts that will be migrated exist.
- The Hybrid Configuration Wizard has been run successfully, meaning that all aspects of the connectors have been configured. This extends to the Mail Flow Connectors/Federation and MRS Endpoints.
- Mail flow to the migrated account is working successfully, with an MX record pointing either into Exchange Online Protection or still On Premises, depending on your desired cutover state.
- The MRS EndPoint is accessible from inside Microsoft 365, meaning that a test of a single mailbox into the Microsoft 365 tenant has been completed.
The Prerequisites section below offers more detail on how this can be achieved, with links to the various Microsoft articles that facilitate this.
When starting a Hybrid migration project with MigrationWiz, there are a number of prerequisites that need to be completed in your environment before launching the migration. These prerequisites relate to the health and setup of the Exchange and Office 365 tenant and ensure that the system can connect and migrate effectively.
1. The Microsoft 365 Tenant has been created and a valid domain/namespace has been configured.
The Microsoft 365 tenant should have been created and set up with the correct domain name, which should match the on premises system. Tenant configurations can vary greatly depending on the type of implementation you are performing, but the base configuration should be in line with the on-premises Exchange environment that you are migrating from.
2. Azure AD Connect is installed and syncing identities to the Microsoft 365 tenant.
Having valid identities inside the Microsoft 365 tenant is a vital step in the process as it provides the linkage between the on premises and the cloud-based implementation. For details on how the Azure AD Connect is set up and configured, check the Microsoft documentation.
3. Hybrid Configuration Wizard has been run and completed successfully.
4. Access to the MRS (Mailbox Replication Service) endpoints is configured and working.
The MRS endpoint configuration is performed during the Hybrid Configuration Wizard process. Once this is created, and you have connected to the Microsoft 365 tenant PowerShell, it can be tested with the following instructions.
For instructions on how to connect to Exchange Online Powershell use this link
Run the Test-MigrationAvailability cmdlet, specifying the endpoint as your configured version.
Test-MigrationServerAvailability -Endpoint "Hybrid Migration Endpoint - EWS (Default Web Site)"
The output will respond back with a Success/Failure message similar to below.
RunspaceId : 785717df-80ce-4148-baff-2b6aad962bfb
Result : Success
SupportsCutover : False
TestedEndpoint : Hybrid Migration Endpoint - EWS (Default Web Site)
IsValid : True
ObjectState : New
In the event of a failed state, the Hybrid Troubleshooting steps on the Microsoft site are useful in ascertaining the issue.
5. A test migration of a single mailbox has been completed successfully using the native toolset.
To confirm that everything is indeed working exactly as expected, we recommend performing a single mailbox migration, using a test or pilot mailbox, can be run manually against the infrastructure. This checks that the entire end-to-end Hybrid environment that has been set up is migrating data, performing look-ups for Free/Busy status, providing correct mail flow, and verifying address book look-ups.