Twice now i've been hit with a DoS attack on the pop3 port which will crahs the mail server. Maybe im doing something wrong but i added the IP to the iptables via the PPP and. The attack continued (i tailed the maillog). I put the ip in the iptables to reject any destination and inserted it at the top of the list. i finnally had to add a null route to make it stop. Any input on how this can be averted? Or why iptables would not immediately stop the attack?