Wp-ban ip plugin wont work

As a general rule, IP bans do not work because spammers have too many ways to bypass them. They can ‘spoof’ the IP, or use alternate IPs.

Also, if your IP Ban plugin sends back a message, spammers know they have a live site and will increase the attempts to spam it.

I think Akismet is a better answer to the spam problem.

Just my opinion.