Luigi Cavalieri

RedBrick is able to block most of the automated spam comments a WordPress blog receives daily.
It is based upon a score system that ensures spam comments are blocked as soon as possible, so as to minimise the number of checks each comment must go through. When in doubt, RedBrick always holds the comment in the moderation queue. Comments identified as spam, however, never reach the database.
As a last resource in discerning the kind of comment under examination, RedBrick takes account also of the comment author’s history.
The plugin is designed to work on low-to-medium traffic blogs.

RedBrick

Simple anti-spam plugin for WordPress blogs.

Milan Dinić

Ryan Hellyer

Bjørn Johansen

Brian Layman

Stops automated spam while remaining as unobtrusive as possible to regular commenters. <a href="https://geek.hellyer.kiwi/products/spam-destroyer/" rel="nofollow ugc">The Spam Destroyer plugin</a> is intended to be effortless to use. Simply install, and enjoy a spam free website 🙂
<h3>Credits</h3>
<ul>
<li><a href="https://wordpress.org/support/users/omahoung/" rel="ugc">omahoung</a> – Bug reporting</li>
<li><a href="https://wordpress.org/support/profile/stromhalm" rel="ugc">Stromhalm</a> – Bug reporting</li>
<li><a href="http://ocaoimh.ie/" rel="nofollow ugc">Donncha O Caoimh</a> – Developer of Cookies for Comments, functionality of which is incorporated into Spam Destroyer</li>
<li><a href="http://elliottback.com/" rel="nofollow ugc">Elliot Back</a> – Developer of WP Hashcash, functionality of which is incorporated into Spam Destroyer</li>
<li><a href="http://nettsett.no/" rel="nofollow ugc">Marte Sollund and Ingvild Evje</a> – Bug reporting</li>
<li><a href="http://eHermitsInc.com/" rel="nofollow ugc">Brian Layman</a> – Code advice</li>
<li><a href="http://ronalfy.com/" rel="nofollow ugc">Ronald Huereca</a> – JS advice</li>
<li><a href="https://twitter.com/shawngaffney" rel="nofollow ugc">Shawn Gaffney</a> – Bug reporting</li>
<li><a href="http://konstruktors.com/" rel="nofollow ugc">Kaspars Dambis</a> – Bug reporting</li>
<li><a href="http://www.wanderingjon.com/" rel="nofollow ugc">Jon Brown</a> – Added error message filter</li>
</ul>

Spam Destroyer

Kills spam dead in it's tracks. Be gone evil demon spam!

RedBrick vs Spam Destroyer