Justin Parr

<h3>Update: 6/2015</h3>
<p>Changed e-mail token and math problem confirmation logic.  Previously, everything happened all at once, and the user would get prompted mutliple times for the math problem.<br />
Now, the user must answer the math problem first, before the e-mail token is sent.  Once the math problem is correctly answered within the session, it isn’t asked again.  The user must now enter the correct token, which results in successful registration.<br />
SPECIAL THANKS TO OLEG M. FOR HELPING ME IDENTIFY, FIX, AND TEST THE ERROR!!</p>
<h3>Update: 5/2015</h3>
<p>Added E-mail confirmation token.  Prevents registration until user enters a token sent via e-mail.</p>
<h3>Features:</h3>
<ul>
<li>Prevent users from registering, if their IP or e-mail address is listed in the “Comments” blacklist (Settings..Discussion)</li>
<li>E-mails user a 4-digit token, and requires the user to enter the token in order to register.</li>
<li>Users must solve a simple math problem (Add two one-digit numbers).</li>
<li>Places user IP address in “Website” field.</li>
</ul>
<p>This is a super-simple user registration spam countermeasure.  I searched for a plugin that was SIMPLE and EFFECTIVE.  I looked at quite a few plugins that promised the desired effect, but were either cumbersome, or included too many unneeded or unwanted features.  Likewise, there are some very simple plugins that are less-than-effective.</p>
<h3>This plugin is VERY simple:</h3>
<p>If the user’s IP or e-mail address is listed in the “Discussion” comments blacklist, it prevents the user from registering.  This functionality should really be built in to WordPress, so, you’re welcome.</p>
<p>When the user registers, they are presented with a simple math problem – adding a 3-digit number to a 1-digit number.  99% of the “user reg spam” is based on bots being able to attack the basic WordPress registration form.  By adding even a simple math problem, most bots will fail, removing your site as a target of opportunity.  Criminals go after what’s easy – if you make it slightly more difficult for them, they will go after someone else.</p>
<p>Once the user solves the math problem, they are sent a 4 digit token via e-mail, and must enter that token to continue registration.</p>
<p>Finally, knowing the location from where your users register allows you to more effectively evaluate and block the source.  This plugin adds the user’s IP address (at the time of registration)  to the “Website” field.</p>
<p>Go to http://whois.arin.net to find out who they are.  If you decide to block the IP,  add the IP address, part of the IP address, or e-mail domain to the “Discussion” comments blacklist, and ANY user registrations from an IP address matching that pattern will be blocked.</p>
<h3>Configuration</h3>
<h3>To Configure the Plugin:</h3>
<p>NOTE:  NO CONFIGURATION IS REQUIRED.  This plugin is fully-functional using the default values.</p>
<p>In the Plugins page, click “Settings” underneath the “JP User Registration Blacklist” plugin.</p>
<ul>
<li>
<p>Seed:  This value determines how the answer to the math problem is masked.  Periodically change this, to keep the spammers and criminals at bay.  The initial value is randomly-generated.</p>
</li>
<li>
<p>Failed Math Response:  Error message displayed to the user, if they fail to correctly solve the math problem.</p>
</li>
<li>
<p>Rejected IP or E-mail:  Error message displayed to the user, if their IP or e-mail is blocked.  Keep this simple and generic, to keep them from knowing why they are being blocked.</p>
</li>
<li>
<p>Form field name for math problem:  This field name contains the user’s answer to the math problem.  Periodically change this, to keep the bots away.  The initial value is randomly-generated.</p>
</li>
</ul>
<h3>To Block an IP address</h3>
<ol>
<li>In the WordPress Dashboard, go to “Settings…Discuss”</li>
<li>To block all or part of an IP address, add it on its own line to “Comments Blacklist”</li>
<li>To block all or part of an e-mail address, add it on its own line to “Comments Blacklist”</li>
<li>Click “Save”<br />
(For more details, see Examples)</li>
</ol>


JP User Registration Blacklist

Prevent User Registration Spam, and Track New User IP address

CreativeMindsSolutions

<p><a href="https://www.cminds.com/wordpress-plugins-library/email-registration-blacklist-plugin-for-wordpress/" rel="nofollow ugc">Pro Plugin Page</a> | <a href="https://www.videolessonsplugin.com/video-lesson/lesson/email-domain-blacklist-plugin/" rel="nofollow ugc">Videos</a> | <a href="https://creativeminds.helpscoutdocs.com/category/285-email-registration-blacklist-cmrb" rel="nofollow ugc">User Guide</a></p>
<p><strong>Safeguard your WordPress site from unauthorized registrations and spammers by implementing personalized rules for blacklisting and whitelisting with our WordPress blacklist plugin solution.</strong></p>
<p>This plugin allows you to block or allow users to enter your website based on specific criteria. With customizable domain, IP and email blacklists you can prevent users from registering.</p>
<p>Conversely, thanks to the whitelist feature of our WordPress plugin, you can ensure that only users with approved email domains, usernames, or IP addresses can register.</p>
<h3>Enhance WordPress Site Security</h3>
<p>Our blacklist plugin enables you to increase the security of your WordPress site and prevent spam registrations from fake or malicious users.</p>
<p>Additionally, this feature-packed tool gives you greater control over who can access your site’s and community content.</p>
<h3>Email Blacklist and Anti-Spam plugin Premium Editions</h3>
<p>The <a href="https://www.cminds.com/wordpress-plugins-library/email-registration-blacklist-plugin-for-wordpress/" rel="nofollow ugc">Email Blacklist and Anti-Spam Plugin Premium editions</a> includes even more powerful features, such as: support for contact forms and WordPress comments, white list and blacklist features work across domains and emails, domain and email testing tool and much more.</p>
<h3>Email Blacklist and Anti-Spam plugin Introduction Video</h3>
<div class="embed-vimeo" style="text-align: center;"><iframe loading="lazy" src="https://player.vimeo.com/video/123027044" width="750" height="422" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe></div>
<h3>How to Use the Email Blacklist Feature of the Plugin</h3>
<ul>
<li><strong>Closed Beta</strong> – Control users in your beta site release.</li>
<li><strong>Members Only</strong> – Add suspicious domains to the blacklist and block their users from registrating.</li>
<li><strong>Spam blocker</strong> – Prevent spam users from registering.</li>
</ul>
<h3>Basic WordPress Blacklist Plugin Features</h3>
<ul>
<li>Support Free Domain List from SpamAssassin.</li>
<li>Support a domain whitelist plugin feature.</li>
<li>Support an email blacklist plugin feature.</li>
<li>Support an IP whitelist plugin feature.</li>
<li>Admin can edit front-end labels and messages.</li>
<li>Includes tester.</li>
</ul>
<h3>Pro Version</h3>
<p><a href="https://www.cminds.com/wordpress-plugins-library/email-registration-blacklist-plugin-for-wordpress/" rel="nofollow ugc">Pro Version Detailed Features List</a></p>
<ul>
<li>Support DNSBL online service.</li>
<li>Support domain blacklist and whitelist features.</li>
<li>Support email blacklist and whitelist features.</li>
<li>Support IP blacklist and whitelist features.</li>
<li>Control who is allowed to comment.</li>
<li>Access to failed registration log.</li>
<li>Additional errors messages to show to users trying to register.</li>
<li>Edit profile restriction.</li>
<li>Support importing list of emails from CSV.</li>
<li>Includes domain & email tester.</li>
<li>Special Gmail support.</li>
<li>Special characters support.</li>
<li>Contact Form 7 integration.</li>
<li>ChatGPT integration.</li>
</ul>
<h3>Follow Us</h3>
<p><a href="https://www.cminds.com/category/wordpress/" rel="nofollow ugc">Blog</a> | <a href="http://twitter.com/cmplugins" rel="nofollow ugc">Twitter</a> | <a href="https://www.linkedin.com/company/creativeminds" rel="nofollow ugc">LinkedIn</a> | <a href="https://www.youtube.com/user/cmindschannel" rel="nofollow ugc">YouTube</a> | <a href="http://www.pinterest.com/cmplugins/" rel="nofollow ugc">Pinterest</a> | <a href="https://www.facebook.com/cmplugins/" rel="nofollow ugc">Facebook</a></p>
<h3>Suggested Plugins by CreativeMinds</h3>
<p>List of all <a href="https://www.cminds.com" rel="nofollow ugc">WordPress Plugins</a> by CreativeMinds</p>
<ul>
<li><a href="https://glossaryplugin.com/" rel="nofollow ugc">CM Tooltip Glossary</a> – Easily creates a Glossary, Encyclopaedia or Dictionary of your website’s terms and shows them as a tooltip in posts and pages when hovering. With many more powerful features.</li>
<li><a href="https://www.downloadmanagerplugin.com/" rel="nofollow ugc">CM Download Manager</a> – Allows users to upload, manage, track and support documents or files in a download directory listing database for others to contribute, use and comment upon.</li>
<li><a href="https://www.answersplugin.com/" rel="nofollow ugc">CM Answers Plugin</a> – A fully-featured WordPress Questions & Answers Plugin that allows you to build multiple discussion forum systems Just like StackOverflow, Yahoo Answers and Quora, Now with MicroPayments and Anonymous posting support.</li>
<li><a href="http://restrictcontent.com/" rel="nofollow ugc">CM Restrict Content</a> – A full-featured, powerful membership solution and content restriction plugin for WordPress. Support access by role to content on your site.</li>
<li><a href="http://bookingcalendarplugin.com/" rel="nofollow ugc">CM Booking Calendar</a> – Customers can easily schedule appointments and pay for them directly through your website.</li>
</ul>


CM E-Mail Blacklist – Simple email filtering for safer registration

The most people are using free emails like aol gmail freenet gmx and so, why to forbid them. And spammer users are using m.niepytajnic1.info.pl
weihnachts-gruesse.info
cbdolejki.pl 

or so. There is no blacklist for them.

I really don't understand the sinn of this plugin

Useless

Block unwanted email registrations on your site with this email blacklist plugin. Protect your site by preventing spam sign-ups.

JP User Registration Blacklist vs CM E-Mail Blacklist – Simple email filtering for safer registration