Sure, your Exchange could be hosted in any domain including your root in the Forest and could host any users from this Forest. However, you need to ensure that domainprep is run on your child domains. James Chong ________________________________ From: exchangelist-bounce@xxxxxxxxxxxxx [mailto:exchangelist-bounce@xxxxxxxxxxxxx] On Behalf Of Anthony Paillard Sent: Friday, September 15, 2006 2:48 AM To: exchangelist@xxxxxxxxxxxxx Subject: [ExchangeList] Exchange deployement in multiple active directory domain Hi, I had to deploy exchange on a multiple domain configuration (mainsite.local, site1.mainsite.local, site2.mainsite.local ...) Can i install one unique server on root domain and set all mailboxes on it ? Does a user on a child domain could have his mailbox (user@xxxxxxxxxxxxxxxxxxxx) on the exchange server set on the root domain ? Each branch are connected trough vpn (about 1O users per site), what is the best connection to the server, outlook direct, rpc / https ? Thank you for your advice Anthony Paillard