Win2k3 Forest, All servers are Win2k3 Parent Domain: parent.com Child Domain 1: child1.com, child1DC Child Domain 2: child2.com, child2DC Can we have separate Exchange 2007 installations on Child1 and Child2? Reason for this is we are trying to merge 2 companies, but we want each one to have it's own Exchange and AD infrastructure. Also, read a few posts that state you can have only one Exchange organization per forest. What does this exactly mean and how will this affect the above? ________________________________________________________________ Depending on how the above info is answered, I have this other issue. Exchange 2007 is up and running on child1 domain, but when trying to install on child2, I get this error when setup checksa;; 4roles I want the server to handle: Setup encountered a problem while validating the state of Active Directory: Failed to create a connection to any of the servers in the topology provider netstat shows nothing is being blocked, and the DC seems to be running fine. Running DCdiag on the DC does not show any issues, and a search for this error does not return anything useful anywhere. Nothing is recorded in the event logs as to the cause of the problem. Any suggestions?

The limitation of "one exchange organization" probably won't impact your design requirements. This just means that the exchange deployment will be recognized forest-wide, and you can't install additional exchange servers without them having at the least recipient and topology awareness of previously deployed servers. You can however have Exchange deployed throughout multiple domains in a single forest, and delegate administrative responsibility and ability to given security groups. This means you can have ABC company utilizing Exchange servers in child1 and XYZ staff utilizing servers in child2. You can also route mail accordingly by using connectors. You should read this for more information (some good graphics too): http://technet.microsoft.com/en-us/library/bb123567.aspx Regarding that error, did you properly "prepare" the forest and each domain for Exchange deployments? This happens sorta-automatically on the first install (depending on where you do so) but not for subsequent domains. See here: Q: What does Setup/PrepareSchema for Exchange 2007 do? A: For detailed information, see How to Prepare Active Directory and Domains. Q: What does Setup/PrepareAD for Exchange 2007 do? A: For detailed information, see How to Prepare Active Directory and Domains. Q: What does Setup/PrepareDomain for Exchange 2007 do? A: For detailed information, see How to Prepare Active Directory and Domains. (also see Table12PrepareAllDomains parameter) http://technet.microsoft.com/en-us/library/bb288906(EXCHG.80).aspx