How to stop spam in smf forum. Problem how do you know if the ip is a spammer?

[james]

Spam is quite a problem when running guestbooks and forums.
Most forums and guestbook’s record details of ip address.
You can block these quite easily from the admin section.
But the problem how do you know if the ip is a spammer?

Check the ip address with http://stopforumspam.com/
Stop Forum Spam
Will catch a lot of spammers trying to register on forums.
We currently have information on 703989 spammers since about December 2006. You can enter an IP address, email address, or username below to search.