I've recently implemented Exchange 2003 in my customer's main office, in this office all the users are working correctly with Outlook. The problem appears when they are sending e-mails to other users from another offices (these external offices are not working with exchange server but working with the ISP mailbox directly), exchange can not send the email, because it's not able to find this external user.
Could be solved with any kind of rule into Exchange??? All the users from all the offices are working within same domain "@aaa.com"
Thanks very much in advance!