ISP REDUNDANCY PROBLEM

[nicopag]

Hi, i am having this problem since i have installed the ISP R. option in my splat.
I have the ISP 1 with the public IP 200.1.1.1 and the ISP 2 with IP 200.2.2.2
I have a DMZ with 2 internal firewalls, one to the client 1 and other tho the client 2.
The problems cames when someone inside the client 2 whants to send a email to client 1, I thank that the problems is in the checkpoint configuration, because the packet goes out from client 2, then passthrough the internal fw of client 2, then goes to the checkpoint looking for the ip of the client 1 smtp server and that IP is in the checkpoint (200.1.1.1) and the packet never goes to the client 1 smtp server.
If I look in the tracker evrything its Ok.
SO, I need to know how to get traffic from client 1 to client 2 without having this kind of problems.
thanks

Sorry about my english