tomroyal

This is a simple plugin designed to cut down on automated spam registrations and the emails they produce.
The idea is simple: in order to register, users have to answer a question that’s simple for anyone reading your blog, but impossible for a script being run by a spammer.
To install, simply copy stop_registration_spam.php to your Plugins directory. Enable the plugin and an options page will appear under the WordPress Settings menu.
In the settings page, enter your question (keep it short), answer (ideally very short) and a hint to display if the user gets it wrong. Save these and they’ll be used for new registrations.
I’ve been using this plugin for a few months, and it cut spam from dozens a day to none at all. Hope you find it useful. Questions etc welcome on my blog:
http://www.tomroyal.com/blog/2012/04/09/stop-wordpress-registration-spam/
Tom

Stop Registration Spam

Stops spammy automated user registrations using a custom question.

Till Krüss

A lightweight plugin that protects plain email addresses and mailto links from email-harvesting robots, by encoding them into decimal and hexadecimal entities. Has an effect on the posts, pages, comments, excerpts, text widgets and other filtered content. Works without JavaScript — just simple spam protection.
To see whether all your email addresses are properly protected, use the free <a href="https://encoder.till.im/scanner?utm_source=wp-plugin&utm_medium=readme" rel="nofollow ugc">page scanner</a> tool.
Other content (like phone numbers) can be protected using <code>[encode]</code> shortcode:
<pre><code>[encode]+1 (555) 123-4567[/encode]
[encode link="tel:+15551234567"]+1 (555) 123-4567[/encode]
</code></pre>
<h4>Premium Features</h4>
<ul>
<li>Full-page protection that catches all email addresses</li>
<li>Hardened protection using JavaScript and CSS techniques</li>
<li>Improved phone number protection</li>
<li>Built-in plugin support for ACF, Jetpack, WooCommerce and many others</li>
</ul>
Check out the <a href="https://encoder.till.im/download?utm_source=wp-plugin&utm_medium=readme" rel="nofollow ugc">Premium</a> version of Email Address Encoder.
<a href="http://coderisk.com/wp/plugin/email-address-encoder/RIPS-r0bJqKvBws" rel="nofollow ugc"></a>

Email Address Encoder


This might work with page or post content, but does not with widgets. I can't recommend using this and suggest to use the plugin "Email Encoder" by Jannis Thuemming instead, since that does the job out of the box.


Not working with widgets

A lightweight plugin that protects email addresses from email-harvesting robots, by encoding them into decimal and hexadecimal entities.

Stop Registration Spam vs Email Address Encoder