Wan1 doesn't route to wan2

I have got fortigate 200D model, and i build on it a simple configuration. wan1 is connected to an isp and wan2 is connected to another isp. wan1 is connected internally to a servers that control the domain and mail server and web server, and VIPs is configured through wan1 port, and wan2 is connected internally to another server that serve anther hosts through policy route on the fortigate. everything is giong to be ok and access to the internet except one thing, hosts that connected to wan2 cant access to the mail site or the web site hosted through wan1. I create policies on the firewall wan2-->wan1 but it doesnt work.

anybody can give me a solution?