I have 1 postfix server that recives mail for "domain1.com"
I also have an Exchange server the recieves mail for "domain2.com"
The two of them are on the same private subnet.
Most users use the postfix server to send email
I would like the postfix server to relay any mail with a final destination of "domain2.com" to the exchange server instead of looking up an MX server, and sending the message over the Internet only to have it come back to the exchange server on the LAN.