codicone

The whitelist/blacklist plugin gives you a strong layer of security for your website because not only does the plugin limits unauthorized user access to your site but also creates a log. The log helps to create new blacklist entries. The increase in your blacklist entries means a decrease in spam and security threats. So it is a great safety measure to start with.
It is a very handy plugin that you can add to your WordPress site for added security. It helps you to tailor your preferences about which email addresses you want to allow for registration on your site.
You can create a list of all email addresses or email domains that you wish to receive registrations. On the other hand, you can add a list for blacklist domains to not allow any registration from specific domains. Blacklisting is time-saving because most of the time you have already figured where the spam comes from. So you close those doors already. It is relatively safe also because you are not risking anything prospective.
<h4>Compatible With</h4>
<ul>
<li>WooCommerce</li>
<li>bbpress</li>
<li>buddypress</li>
<li>Profile Builder</li>
<li>WP User Frontend</li>
<li>User Registration</li>
<li>Ultimate member</li>
</ul>

Blacklist & Whitelist Domains for Registration

The whitelist/blacklist plugin gives you a strong layer of security for your website because not only does the plugin limits unauthorized user access  …

Anthony

This plugin will limit access to the site. Only visitors with a cookie token will be able to access the public website. Visitors without the cookie will see a “coming soon” style of page.
You can customise the “coming soon” content, and you can change the way tokens work. Visit yoursite.com/?add_token to receive the token allowing you to see the site. To remove the limited access, simply disable this plugin.
By default, the token is “letmein”. So use these links: 
site.com?letmein 
site.com?takemeoff
This plugin is useful when you’re developing your site. You can work on your live web server without having your site open to the public.

Token Access

Limit access to the site to those with a cookie token.  Visitors without the cookie see a customisable "coming soon" style of page.

Blacklist & Whitelist Domains for Registration vs Token Access