Redirect mail traffic to a specified server

This is if you want to redirect all traffic through your router to your own specified mail server. This is usefull if you have many clients from different locations connecting to your network at different times. (Note that if you are using Hotspot you can do this in the Hotspot settings instead)
ip firewall nat add chain=dstnat protocol=tcp dst-port=25 action=dst-nat to-addresses=10.0.0.1 to-ports=25

This will redirect all smtp (port 25) traffic out the router to ip address 10.0.0.1