I want that WAN1 transports only my external smtp trafic and WAN2 to handle all the remnant trafic. I can't figure out how to configure my two WANs (priority or administrative distance) end my policy route to make that happen.
I believe to use both WANS simultaneous the priority and admin distance need to be the same, Otherwise, the one with the lower priority would be the route the traffic follows. Once that is completed and traffic is using both internets, I would think creating a specific outbound rule to WAN1 only allowing smtp traffic and place it before any other outbound rules would do it. You may consider setting up a link monitor so that if the circuit goes down your smtp traffic could go out the other circuit. I am no expert by any means but that is what I would try.
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.