Now that multi-tenancy and hosting is officially supported with the release of the Exchange Server 2010 SP2, Microsoft released additional technical information about the subject:
- Multi-Tenancy and Hosting Guidance for Exchange Server 2010 SP2
A multi-tenant Exchange deployment is defined in this document as one where the system has been configured to host multiple and discrete organizations or business units (the tenants) that ordinarily do not share e-mail, data, users, global address lists, or any of the other commonly used objects in Exchange.
This document does not provide step-by-step instructions about how to achieve multi-tenancy with Exchange 2010 SP2, but provides information on the challenges and problems that need to be solved, and offers advice and direction to ensure the Exchange environment that you build can be supported by Microsoft. - Exchange 2010 SP2 Multi-Tenant Scale Guidance
This document contains high-level guidance for properly scaling and deploying a multi-tenant Microsoft Exchange Server 2010 Service Pack 2 solution. It includes details of testing performed in Microsoft labs to validate the scalability of the product and suggests methods that can be used during the design and deployment process to mitigate potential risks associated with such solutions.