How to block spam IP iptables

Question

My server is getting hammered with spamming. How do I block these two IP addresses from sending emails? What's the iptables command to block these IP addresses?

http://pastebin.com/vt4qei89

Thanks!

Answer 1

The best way of using iptables for blocking a large number of IP-addresses is by using ipset. It acts as a "database" of IPs, allowing iptables to quickly look up an IP and decide whether to block it or not.