Exchange 2003 point to new forest?

[tazz]

Insane question but here goes..

Setting up a new domain with a new forest. Intend to use AD migration tool to transfer over user accounts.

Want to keep the exisitng Exchange 2003 server but point it to the new forest. Is this possible or am I looking art re-installing Exchange when every thing elese is sorted?

Thanks

[FN-GM]

I have been told the only way is to to install Exchange on the new forest then migrate the mailboxes accross to the new exchange server on the new domain.