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If I send or recieve mail I get logs about port 25. that I opent.
Also my backend machines cannot surf or ftp.
So what is going on, please help..
Here is my firewall script:

#Point this to your copy of ip_tables
IPT="/usr/local/sbin/iptables"

# Flush old rules, delete the firewall chain if it exists
# Setting standard filter policy on DROP
$IPT -F
$IPT -P INPUT DROP
$IPT -P OUTPUT DROP
$IPT -P FORWARD DROP
$IPT -F -t nat
$IPT -X firewall
$IPT -Z

#Set up the firewall chain
$IPT -N firewall
$IPT -A firewall -j LOG --log-level info --log-prefix Firewall:
$IPT -A firewall -j REJECT

# Enable IP Forwarding, if it isn't already
echo 1 > /proc/sys/net/ipv4/ip_forward

# Refuse incoming packets pretending to be from the external adress
$IPT -A INPUT -s $EXTIP -j firewall

# remote interface, claiming to be local machines, IP spoofing, get lost
$IPT -A INPUT -i $EXTIF -s $LOCALNET -d $UNIVERSE -j firewall

# outgoing to local net on remote interface, stuffed routing, deny
$IPT -A OUTPUT -o $EXTIF -s $LOCALNET -d $UNIVERSE -j firewall

# Loopback interfaces are valid
$IPT -A INPUT -i lo -s $UNIVERSE -d $UNIVERSE -j ACCEPT
$IPT -A OUTPUT -o lo -s $UNIVERSE -d $UNIVERSE -j ACCEPT

# Local interface, local machines, going anywhere is valid
$IPT -A INPUT -i $INTIF -s $IPNET -d $UNIVERSE -j ACCEPT
# All internal machines have access to the firewall machine
$IPT -A INPUT -i $INTIF -s $LOCALNET -j ACCEPT
$IPT -A OUTPUT -o $INTIF -d $LOCALNET -j ACCEPT

# Accept DNS, 'cause it's warm and friendly
$IPT -A INPUT -p udp --sport 53 -j ACCEPT
$IPT -A INPUT -m multiport -p tcp --sport 42,53 -j ACCEPT
$IPT -A OUTPUT -m multiport -p tcp --dport 42,53 -j ACCEPT
$IPT -A OUTPUT -p udp --dport 53 -j ACCEPT

# Allow SSH to this server.
$IPT -A INPUT -p tcp --dport 22 -j ACCEPT
$IPT -A INPUT -p udp --dport 22 -j ACCEPT
$IPT -A OUTPUT -p tcp --sport 22 -j ACCEPT
$IPT -A OUTPUT -p udp --sport 22 -j ACCEPT

# Setting up SMTP Server (25)
$IPT -A INPUT -i $EXTIF -p tcp --dport 25 -j ACCEPT
$IPT -A OUTPUT -o $EXTIF -p tcp --sport 25 -j ACCEPT

# Allowing SMTP Client (25)
$IPT -A OUTPUT -o $EXTIF -p tcp --dport 25 -j ACCEPT

# Reject incoming and outgoing traffic to port 137,138,139 Net BIOS
$IPT -A INPUT -p tcp --dport 137:139 -j REJECT
$IPT -A OUTPUT -p tcp --dport 137:139 -j REJECT
$IPT -A INPUT -p udp --dport 137:139 -j REJECT
$IPT -A OUTPUT -p udp --dport 137:139 -j REJECT

# Allow EXTERNAL access to the Webserver
$IPT -A INPUT -i $EXTIF -p tcp --dport 80 -j ACCEPT
$IPT -A OUTPUT -o $EXTIF -p tcp --sport 80 -j ACCEPT

#Setup Masquerading.
$IPT -t nat -A POSTROUTING -o $EXTIF -j MASQUERADE

# Catch all rules
$IPT -A INPUT -s $UNIVERSE -d $UNIVERSE -j firewall
$IPT -A OUTPUT -s $UNIVERSE -d $UNIVERSE -j firewall
$IPT -A FORWARD -j firewall

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