When operating in transparent mode, the FortiMail unit can use either transparent proxies or an implicit relay to inspect SMTP connections. If connection pick-up is enabled for connections on that network interface, the FortiMail unit can scan and process the connection. If not enabled, the FortiMail unit can either block or permit the connection to pass through unmodified.
First, configure the outgoing proxy pick-up settings.
- Go to System > Mail Setting > Proxies.
- Enable Use client-specified SMTP server to send email and click Apply.
- Go to System > Network > Interface.
- Edit SMTP proxy settings for both port2 and port3. Under SMTP Proxy:
- Set Incoming connections to Drop.
- Set Outgoing connections to Proxy.
- Disable Local connections.