Very light invisible method to block auto-spam when spam comment is posted. Pings and trackbacks cheks for real backlink.
Bad Behavior prevents spammers from ever delivering their junk, and in many cases, from ever reading your site in the first place.
Integrates reCAPTCHA anti-spam methods with WordPress including comment and registration spam protection.
Comment Spam Prevention without CAPTCHA. No CAPTCHA, No SPAM!
The fight against spam in comments by free service Yandex .NET Web
WPshore Contact Form 7 Spam Prevention helps you manage your Inbox to keep it free of unwanted e-mail messages.
This antispam plugin provides very simple(one-click) and powerful captcha for your blog.
Write email addresses without worrying about spambots and email harvesters.
Antispam for bbPress 2.x
This Plugin provides a Shortcode to encrypt email addresses / links and protect them against spam.
An easy to use wordpress Captcha plugin to prevent spam on your site. You can use Image Captcha to protect comments and the admin panel.
Prevent spams with hassle free captcha.
Todd Lahman's comment spam blocking plugin that blocks automated spam with zero false positives.
This plugin will make your blog more secure by adding rules which spambots will not pass.
The Advanced WordPress Security plugin Developed by World Web Arts to protect your wordpress website from virus and malicious attack by permission set
WP True Typed is an anti-spam plugin to protect your site from comment spam.
Extremely simple, 0 configuration and 0 user/admin-interaction anti-spam plugin.
Provides better email validations to protect your blog from spam comments and bots creating accounts.
Super Simple Anti Spam for WordPress is anti spam plugin (for comments and trackbacks), while not having to moderate and / or edit a single setting.
minotaur - Rid the internet of text CAPTCHAs!
This plugin protects your registered user base by preventing registration with a disposable email addresse (like the ones provided by mailinator).
This plugin adds a new form of captcha to your Buddy Press registration and comment forms. Use this plugin to prevent bots from spamming your website
This plugin is a simple captcha that appears when an unregistered user try to register or to leave a comment.
Add Hashcash spam protection to Contact Form 7.
Keep Your Site Happy, add Khush Captcha Anti-SpamBot Technology to your WordPress Registration and Comment Forms.
minteye - STOP SPAM, MAKE MONEY!
Plug-in to hide the login page, change the url: wp-login.php and wp-admin maintaining functionality
A plugin to understand SpamDyke 's error codes
Several types of captcha to protect your site in one easy to use plugin.