#!/bin/sh -

iptables -F

LAN_IF="eth0"
SMTP_LAN="10.12.0.2,10.12.0.10"

# SMTP 
iptables -A INPUT -p tcp -i $LAN_IF -s $SMTP_LAN --dport 25 -j ACCEPT
iptables -A INPUT -p tcp -i $LAN_IF --dport 25 -j REJECT

exit