Cross-Tenant Identity Mapping (preview)

Cross-Tenant Identity Mapping is a feature that can be used during Cross-Tenant User Data Migrations from one Microsoft 365 organization to another. It provides a secure method of establishing one-to-one object relationships across organization boundaries, and automatically prepares the target objects for a successful migration.

Cross-Tenant Identity Mapping removes the need to export large data sets from a source organization for the sole purpose of configuring Mail Enabled User objects in the target organization.

With Cross-Tenant Identity Mapping, data remains within the Microsoft security boundary and is securely copied directly from the source organization to the target organization using specially configured Organization Relationships serving as a unidirectional trust.

Using Cross-Tenant Identity Mapping reduces mistakes when configuring target objects for a migration by automatically configuring values such as ExchangeGuid, ArchiveGuid, and all necessary X500 proxy addresses.

Some additional benefits of using Cross-Tenant Identity Mapping:

• Reduces the number of manual processes where a mistake may result in failed migrations
• Automates identification of objects within scope to migrate from the source organization to the target organization
• Establishes a 1:1 map of a Mailbox User object in the source organization to a pre-existing Mail Enabled User object in the target organization
• Automates population of required attributes from the source organization Mailbox User to the target organization Mail Enabled User
• Provides a list of objects prepared and ready for cross-tenant mailbox migration based on the source organization users' primarySMTPAddress value

We would like to provide information commonly asked so you may evaluate if you would like to participate in the private preview.

• The feature is only intended to be used with Cross-tenant mailbox migration, and not with any third-party non-Microsoft migration solutions.
• Data processing (storage, compute, transfer, etc.) is currently within the European Union, and within the Exchange Online home region of the organizations participating in the migration.
  • For Multi-Geo enabled organizations, the organization's home geo for Exchange Online will be used.
• This feature can currently only be enabled in the worldwide Microsoft 365 offering. It doesn't work in GCC, GCC High, DoD, Office 365 by 21 Vianet, etc.
• Cross-Tenant Identity Mapping does not create the Mail Enabled User objects in the target tenant for you. These objects must still be created with a minimal attribute set. Once created, then Cross-Tenant Identity Mapping decorates their attributes correctly for a mailbox migration to proceed.
• Some familiarity with PowerShell is currently required as the feature is PowerShell-based
• The feature communicates over an encrypted connection to a REST endpoint.
• The feature currently requires the Global Administrator role for initial setup. This behavior may change in a future update.
• Organizational Relationships are used as a dual handshake approach to ensure both organizations have authorized this transaction type to take place.
• It works with cloud-only or hybrid organizations.
• Target organizations in a hybrid configuration require Microsoft supported on-premises object management tools to modify any Mail Enabled User objects synchronized from the on-premises directory.

We're looking for customers willing to both try Cross-Tenant Identity Mapping and to provide feedback based on their experience. Did it make the migration easier for you compared to earlier migrations you've performed? Are there features you feel are missing? All constructive feedback is welcomed.

The Cross-Tenant User Content Migration feature and licenses are currently only available to Enterprise Agreement customers. If you are an Enterprise Agreement customer who will be purchasing Cross-Tenant User Content Migration licenses, and you would like to evaluate Cross-Tenant Identity Mapping to improve your migration experience, then please email CTIMPreview@service.microsoft.com and provide some basic information about the migration you are performing. The team will respond to you within a couple business days with some additional questions. For more information on licensing, please see Cross-Tenant User Content Migration Licensing and contact your Microsoft account team.

We recommend reviewing the current Cross-Tenant Mailbox Migration steps related to preparing target user objects for migration as this preparation is what Cross-Tenant Identity Mapping will automate.

• Review Cross-Tenant Mailbox Migration