prevent postfix fro flood attack

[krzysiek]

Hi,
How can I prevent my postfix server from receiving hundreds of mails when each of with is the same? I know that it can be done by using iptables with something like this:

iptables -N syn-flood
iptables -A INPUT -p tcp --syn -j syn-flood
iptables -A syn-flood -m limit --limit 1/min --limit-burst 4 -j RETURN
iptables -A syn-flood -m limit --limit 1/min --limit-burst 4 -j LOG --log-level debug --log-prefix "SYN-FLOOD: "
iptables -A syn-flood -j DROP
iptables -A INPUT -p icmp -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A OUTPUT -p icmp -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT

but it's only part of solution because it only limit number of messages to 5 per minute.
The best solution would be that, when I could block particular email or IP address

[jledhead]

you could try postgrey Postgrey - Postfix Greylisting Policy Server