Hello! I have set up a firewall and a port forward to a webserver/mailserver. I am running the kernel 2.4.9. The forwarding for the port 80 works fine! The mail which come in doesn´t get forwarded for some reason! But the iptables line looks exactly the same as the working ones for the webserver. The mail arrives at the firewall (as i can see when a "new mail has arrived" comes up on my console), but it should go to 192.168.1.40(web/mailserver) Do i need other ports to forward than 25 and 100 ? I set all policies onto ACCEPT, just to be sure. Port 80 works totally fine!! iptables -F OUTPUT iptables -F INPUT iptables -F FORWARD iptables -t nat -F PREROUTING iptables -P OUTPUT ACCEPT iptables -P INPUT ACCEPT iptables -P FORWARD ACCEPT iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE echo 1 > /proc/sys/net/ipv4/ip_forward iptables -t nat -A PREROUTING -p tcp --dport 80 -i ppp0 -j DNAT --to 192.168.1.40:80 iptables -t nat -A PREROUTING -p tcp --dport 25 -i ppp0 -j DNAT --to 192.168.1.40:25 iptables -t nat -A PREROUTING -p tcp --dport 110 -i ppp0 -j DNAT --to 192.168.2.40:110 iptables -t nat -A PREROUTING -p udp --dport 25 -i ppp0 -j DNAT --to 192.168.1.40:25 iptables -t nat -A PREROUTING -p udp --dport 110 -i eth0 -j DNAT --to 192.168.2.40:110 ~# iptables -t nat -L PREROUTING Chain PREROUTING (policy ACCEPT) target prot opt source destination DNAT tcp -- anywhere anywhere tcp dpt:www to:192.168.1.40:80 DNAT tcp -- anywhere anywhere tcp dpt:smtp to:192.168.1.40:25 DNAT tcp -- anywhere anywhere tcp dpt:pop3 to:192.168.2.40:110 DNAT udp -- anywhere anywhere udp dpt:25 to:192.168.1.40:25 DNAT udp -- anywhere anywhere udp dpt:pop3 to:192.168.2.40:110 I hope you know what i mean, and you can maybe help me/give me a hint. Thank you Spiekey