IPTABLES SOS

[Craig]

Goodday ladies and fella's

I have just installed the new 2.4 kernel on one of my potato boxes and am
fighting with iptables to forward mail from external ip to internal mail
server
ie 1.2.3.4:25 --> 192.168.x.y:25

Has anyone managed to pull this off, and if so can someone please HELP 
me :)

Kind regards
Craig :)

winmail.dat