My sister company has a Cisco 1720 Router. I am installing a Barracuda Spam firewall for them. I need to point port 25 on the 1720 router to the Barracuda Spam firewall so it will filter the mail before it gets to the exchange server. I did this with no problem at my other two companies but we are using Netopia routers which is easier to configure. Could anyone give me the steps to do this on the Cisco 1720 router?