Objective: We want to deploy a single Exchange 2010 Server and have it support the users in its "home" domain and forest as well as users in a separate domain and forest.
Our scenario: We manage 2 domains that are each in their own forest. Neither one currently has an Exchange server. Both are 2003 AD functional level. Both domains have user accounts. DomainA is located in ForestA, and DomainB is located in ForestB. A domain trust between DomainA and DomainB has been configured and is working properly. We want to deploy Exchange 2010 to DomainA for DomainA users and allow DomainB users to use its services at the same time.
The reason I'm having trouble being certain whether or not DomainA can have user accounts and still be able to deploy Exchange 2010 to DomainA in a Resource Forest Topology is the MS article's description of an Exchange Resource Topology (found at http://technet.microsoft.com/en-us/library/bb124734.aspx
A resource forest topology is one with an Exchange forest and one or more user accounts forests.
That means both ForestA and ForestB in our case are User Accounts Forests.
Here is an overview of what you need to do to deploy Exchange 2010 in a topology with a resource forest:
1.You must have a forest with Exchange installed. In the Exchange forest, you must have disabled the user accounts that have Exchange mailboxes.
So all the users in our DomainA would have to be disabled and they wouldn't be able to log in anymore? We can't do that.
2.You must have at least one forest that contains user accounts. This forest should not have Exchange installed.
So we can't deploy Exchange 2010 to DomainA if we want to simultaneously support DomainB with it?
3.Then, you must associate the disabled user accounts in the Exchange forest with the user accounts in the accounts forest.
When deploying Exchange to a domain with user accounts, aren't the accounts automatically associated with their respective mailboxes?
Obviously, the article was of no use to me in trying to answer our question:
Can DomainA in ForestA also be the Exchange Resource Forest for iteself as well as being the Exchange Resource Forest for DomainB in ForestB?
(DomainB must remain in ForestB).
/reaches for Aspirin...