#? /bin/sh

# reset tables
ipXtables -P INPUT DROP
ipXtables -P FORWARD DROP
ipXtables -F
ipXtables -X


ipXtables -N Retiolum

ipXtables -A INPUT -j Retiolum -i retiolum

ipXtables -A Retiolum -j ACCEPT -p tcp --dport smtp -m conntrack --ctstate NEW


etc.