I see numerous posts of a similar variety but either I'm just too frazzled to put the pieces together right now or they're talking about something different. The term "domain" of course seems to "email domain" in most if not all of the posts I've seen. Oh, did I mention this is probably a really stupid question anyway? Right now I have one Exchange 2K3 SP2 server with no front-end server. I have one AD forest with one domain, we'll call it a.com. We've always run with two email domains for each user in a.com (those being a.com and b.com) and that's been just fine. But now we're acquiring a new entity and they're going to get their own AD domain in the a.com forest, called c.com. I want this one Exchange server to continue reading the a.com AD domain for recipients, but to also read the c.com AD domain for recipients (using c.com as their email domain). I'm assuming that this is just a matter of creating another RUS? TIA

Exchange only works at the forest level. Therefore if you are purchasing another company and they are retaining their forest, then you cannot use their Exchange with your Exchange frontend. You would have to either keep both separate and maintain them like that, or dump their forest, migrate everything in to your forest and possibly build them a new child domain. Simon.Simon Butler, Exchange MVP. http://blog.sembee.co.uk , http://exbpa.com/

Okay, I think that answers my question, but I also think I might not have expressed my question properly. We currently have AD domain a.com in AD forest a.com - this is all we have. For the acquisition, I will be migrating over all their users etc to an AD domain c.com in AD forest a.com using Quest's Migration Manager For Active Directory. So I'll have two domains in the one forest. Since Exchange works at the forest level, you're saying I won't have any issues with it generating recipients in these two domains?

Add "c.com" as an accepted domain in your "a.com" domain. Do some testing, you should be fine.

Add "c.com" as an accepted domain in your "a.com" domain. Do some testing, you should be fine.

Exchange will cope with almost as many of the domains as you like (within reason). If you want automatic email creation then you will have configure recipient policies carefully to ensure that users get the email address that you want them to have. Simon.Simon Butler, Exchange MVP. http://blog.sembee.co.uk , http://exbpa.com/

Hi, Please create the Recipient Policy for that new domain in your Exchange server. Thanks AllenAllen Song

Yeah, I anticipated having to create a new policy, I was just confused on whether the Exchange server would see the other domain. Sounds like everything's good to go. Thanks.

Hi, Of course, that is feasible. Hope to receive your good news. AllenAllen Song