I am looking for the best/cheapest firewall that will do the following
Create a "service" (i.e. Exchange e-mail uses smtp - tcp/25)
Create rules for packet filtering (i.e. "Exchnage service" to accept/forward anything from "External Ip address" to destination "local address of server"
Create rules for NAT port forwarding (i.e. "Exchange Service" to forward anything from "external IP address" to destination "Public IP address of server"
We were using a Snapgear/Mcaffee 560 - It just died on us and now our exchange email is down. I need a possible temp solution as well as the best fit for what we need.