Question : exchange 2007/Route mail to ISP if account is not local.

I am currently trying to move from exchange 2000 to Exchange 2007.  In exchange 2000 if the user account did not exist in active directory then the mail was sent to the ISP.  I have an internal domain that is the same name as the external domain.  I still have some mail accounts that only exist on the external POP3 server.  When i send to these accounts the new 2007 exchange server trys to deliver them locally.  Then I get a NDR saying that the account does not exist.  How do i tell exchange 2007 to send the mail to the external smtp server if the account does not exist local in AD?  

Answer : exchange 2007/Route mail to ISP if account is not local.

You need to create an Internal Relay.

Create a new connector for this and point it to the SMTP address.