*filter
:INPUT DROP
:SERVICE -
-A INPUT -j SERVICE
-A SERVICE -p tcp --dport 22 -j ACCEPT
-A SERVICE -p tcp --dport 25 -j ACCEPT
-A SERVICE -p tcp --dport 80 -j ACCEPT
-A SERVICE -p tcp --dport 143 -j ACCEPT
-A SERVICE -p tcp --dport 443 -j ACCEPT
-A SERVICE -p udp --dport 53 -j ACCEPT
COMMIT