We have a 310 (5.3.9 build 1448) we use to balance three WAN (2 HDSL / 1 ADSL) and we NAT some public IP on private IP to publish some web servers and the internal mail server.
I would ask: is NAT affected by “Firewall in/out” rules and/or by “Outbound policies” ? Or all ports of NATted server is exposed to internet ?
Furthermore: is it better to NAT the entire mailserver’s IP or to “Service” only SMTP/POP 3 ports using “Inbound access -> Services” menu and opening the porst on firewall too ?
I hope i explaned …