HiWe are running Exchange 2003 SP2 in our forest. Forest root is domain.com, and we have child domains of US.domain.com, Canada.domain.com and Japan.domain.com. Exchange org is named Domain.We have an association with a company whose forest is External.com. There is a one way incoming external forest, non-transitive,trust set up between Canada.domain.com and External.com. The description on our side is:"Incoming: Users in the local domain can authenticate in the specified domain, but users in the specified domain cannot authenticate in the local domain."External.com use Exchange 2007 and have their own, entirely seperate, Exchange org.We have some users moving from our company to theirs, and we need to transfer the mailboxes. However, these users' mailboxes are located in the US.domain.com domain.Is it possible to use the Move-Mailbox command at the External Exchange side to move these mailboxes to the External Exchange org? There is some info here on moving mailboxes between forests, but it's not clear whether this is between forests that share an Exchange org.http://technet.microsoft.com/en-us/library/aa997145.aspxThe article says it's possible to move mailboxes from an Exchange 2003 server in one forest to an Exchange 2007 server in another forest using the Move-Mailbox command only. Any ideas? Would they need any permissions set up on the source mailbox - and, if so, how would we do that since there is no direct trust between the US domain and External?Any help appreciated!

Hi It is not possible to move mailbox to the domain External.com, if there is not direct trust between US.domain.com and External.com. So you must build trust relation between the two domains first, and then you can do that. You can refer to below links: http://msexchangeteam.com/archive/2006/11/02/430289.aspx http://technet.microsoft.com/en-us/library/aa997145.aspx Youd better test that in your lab firstly, I have made a test successfully.Hope useful for you.