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.

Adiie9

IP Blacklist Cloud

Blacklist IP Addresses from visiting your WordPress website and Usernames from spamming.  View details of all failed login attempts.

Geek Mail Blacklist vs IP Blacklist Cloud