If you have two AD Sites each with an Exchange 2003 server but plan to upgrade to 2007 and have all of your server roles reside in one site can you move all users across both sites to one mailbox server in Site1 and still have users in Site2 receive mail eventhough they do not actually reside in Site1. I know that each site that has a mailbox server role requires a hub transport server to be installed but if you plan to have your entire exchange environment in Site1 will clients in Site2 still receive mail?

Yes, actually in that case outlook clients in site2 will connect to their mailboxes available on Mailbox server of Site1 without any problem over RPC call but make sure that connectivity is reliable between both sites...Amit Tank | MVP Exchange Server | MCITP: EMA | MCSA: M | http://ExchangeShare.WordPress.com

Thank you for the confirmation and the quick response.