I have 2 clients (one IP 200.x.y.52 and another 200.x.y.47) in ADSL conection and a same gateway (200.x.y.1).
When the server send an email, the error "No route to host" appear.
I used TELNET 200.x.y.52 25 (110 soo) and the error occurr in both servers and both directions. The Firewall was disabled .

what is the subnet on both machines?

255.255.255.0 .. in both servers.

I have a file called mac.txt and inside it contains the following: IP and MAC,
192.168.0.10;F0:AF:FF:FE:FA:00

My script for firewall is as follows:

#!/bin/bash
for i in `cat /root/mac1.txt`;
do
MACSOURCE=`echo $i | cut -d ';' -f1`
IPSOURCE=`echo $i | cut -d ';' -f2`
iptables -t filter -A FORWARD -d 0/0 -s $IPSOURCE -m mac --mac-source $MACSOURCE -j ACCEPT
iptables -t filter -A FORWARD -d $IPSOURCE -s 0/0 -j ACCEPT
iptables -t filter -A INPUT -s $IPSOURCE -d 0/0 -m mac --mac-source $MACSOURCE -j ACCEPT
iptables -t nat -A POSTROUTING -s $IPSOURCE -o eth0 -j MASQUERADE
done
iptables v1.4.3.1: Bad mac address "192.168.0.10"
Try `iptables -h' or 'iptables --help' for more information.
iptables v1.4.3.1: host/network `F0:AF:FF:FE:FA:00' not found
Try `iptables -h' or 'iptables --help' for more information.
iptables v1.4.3.1: Bad mac address "192.168.0.10"
Try `iptables -h' or 'iptables --help' for more information.
iptables v1.4.3.1: host/network `F0:ADF:FF:FE:FA:00' not found
Try `iptables -h' or 'iptables --help' for more information.

Please help me.