Configuring policy-based routes on the router

After you have configured the FortiMail settings, you must create policy routes on the router to redirect the SMTP traffic (from and to the subscribers) to the FortiMail unit for scanning.

For example, on a FortiGate unit as the router/firewall, go to Router > Policy Route to create two routes: one for the external-to-subscribers SMTP traffic and one for the subscribers-to-external SMTP traffic.

For more information, see the FortiGate Handbook.