Multiple MX Records

[igolo]

I need some help with a setup for email.
Setup
I have a PIX525 and an ASA5510VPN and an internal 2950 router. The PIX does firewalling and the ASA does VPN. Currently all outbound Internet traffic goes through the PIX via the router with this command:
ip route 0.0.0.0 0.0.0.0 10.1.1.2 1
The ASA5510 with its dedicated external IP is used to allow VPN traffic in.
The problem:
I have two separate domain names and two MX records. One (mail.PIX.com)is pointed at the external IP of the PIX the other (mail.ASAVPN.com) is pointed at the ASA5510. I can receive inbound mail through both of the devices. I'd like to mail go out using both domains one through PIX and the other thru ASA. The problem is the router says all unknown traffic go to PIX.
How do I route mail from a host (10.1.1.5) to the ASA5510(10.1.1.4), while sending the mail from host (10.1.1.3) to PIX(10.1.1.2)

 

[brianinms]

Use a route map on the router to send all traffic from 10.1.1.5 out the asa