Hello, I'm looking for a Microsoft recommended best practice while installing Exchange 2007. The particular setup is as follows: Active Directory Users are in a child domain. Example, child.mydomain.com. Should Exchange 2007 be installed at the same level in the tree or at the parent domain, i.e., mydomain.com? Any feedback,suggestions would be great! Thanks.

My recommendation would be to put the exchange server in the parent domain. Just make sure you run the necessary prep commands in the child domain:http://technet.microsoft.com/en-us/library/bb125224.aspx

Well, it really depends on how your org planning to spend amount for Exchange Server licensing and CALs, Exchangetopology planing,also with proper resource/hardware sizing, network bandwidth between sites and number of user available in parent or child domain. I would choose the domain where I have large amount of users so they will have local server... And you need to prepare all domain where you are going to have Exchange server or recipients as per the guide given by Jason...Amit Tank | MVP Exchange Server | MCITP: EMA | MCSA: M | http://ExchangeShare.WordPress.com