port 25 forwarding iptables FC4, can't get it to pass traffic
I am trying to to set up port forwarding using iptables to forward all port 25 traffic from my mail server to a spam appliance. The trick is that I want to direct all but traffic from one IP address over to the appliance.
here is the rule I am trying to use...
iptables -t nat -A PREROUTING -i eth0 -p tcp -s !10.x.x.x --dport 25 -j DNAT --to-destination 10.x.x.15:25
Any ideas what I am doing wrong?