In Exchange 2010 a new feature will be available called Address Book Policies which makes it possible to use multiple Address Books in Exchange 2010, completely separated from each other. It is sometimes referred to as multi-tenancy for Exchange 2010 although this is not entirely true. In this article I’d like to explain a bit more.

Address List Segregation

For Exchange 2007 Microsoft has a whitepaper available that describes how to implement Address List Segregation to achieve multiple Address Lists completely invisible for each other. In other words, users in the Contoso.com Address List don’t see other Address Lists and users, like the Fabrikam Address List or the Tailspintoys Address List. In Exchange 2007 this is implemented using Access Control Lists (ACL’s) to set permissions for specific Address Lists. This works fine for Exchange 2007 but Exchange 2010 uses a different technique called the Address Book Service running on the Client Access Server. Therefore, if using (or trying to use) the Address List Segregation whitepaper on Exchange 2010 things will horribly break. Continue reading Exchange 2010 SP2 Address Book Policies →