-- NIC
-- network
-- ethernet

On the MailGate console menu, navigate to the options that configure the networks settings. The only options provided are to configure eth0 and eth1.

Would the other two NIC cards on an 47x0/57x0/67x0 appliance models be configured?

MailGate only supports up to two NICs which is why only eth0 and eth1 are seen in the console menu.