Wagner

<ul>
<li>Block certain kinds of users from registering to your WordPress site by adding blacklist rules. </li>
<li>Super simple to use. The whole plugin just has one simple settings page.</li>
<li>Support regular expression rules.</li>
<li>Completely free.</li>
<li>Support tracking and recording login attempts since v1.1.0.</li>
<li>Login attempts chart since v1.1.0.</li>
</ul>


Geek Mail Blacklist

Block users with certain emails from registering to your WordPress site by adding blacklist rules.

Jake Jackson

<p>If you like total control of the comments on your WordPress blog without having any extra overheads (like you get with 3rd party spam prevention software) then this is a great tool for you.</p>
<h4>Features</h4>
<ul>
<li>Automatically placed IP address on comments blacklist if administrator marks comment as spam</li>
<li>Will remove IP address from comments blacklist if spam item is marked as ‘not spam’</li>
<li>When activated, will review all spam comments and place the spammers IP address on the comments blacklist.</li>
</ul>
<h4>Support</h4>
<p><a href="http://www.blueliquiddesigns.com.au/index.php/wp-automatic-spam-blacklister/" rel="nofollow ugc">All support is provided through the plugin developer’s website</a>.</p>


WP Spam Blacklister

The WP Spam Blacklister is a simple spam-prevention plugin that adds the IP address of a marked spam post on Wordpress' comments blacklist.

Geek Mail Blacklist vs WP Spam Blacklister