byteplant

<h4>Real-Time Email Validation – Live Check</h4>
<p>This plugin uses the Byteplant Email-Validator API (https://www.byteplant.com/email-validator/) for a real-time live check to find out if an email address really exists or not.</p>
<h4>Supported Plugins / Compatible Forms</h4>
<p>The plugin integrates seamlessly with:</p>
<ul>
<li>Contact Form 7</li>
<li>Gravity Forms</li>
<li>WPForms</li>
<li>Ninja Forms</li>
<li>Jetpack/Grunion</li>
<li>WooCommerce</li>
<li>WordPress registration forms</li>
<li>WordPress comments</li>
<li>and with any other form which uses the is_email() function (no changes required).</li>
</ul>
<p>The plugin can also be easily integrated into any 3rd party forms.</p>
<h4>Key Features</h4>
<p>The Email-Validator API real-time validation process includes a live check with all of the following tests:</p>
<ul>
<li>Syntax verification (IETF/RFC standard conformance)</li>
<li>DNS validation, including MX record lookup</li>
<li>Disposable email address (DEA) detection</li>
<li>Misspelled domain detection to prevent Typosquatting</li>
<li>Freemail address detection</li>
<li>SMTP connection and availability checking</li>
<li>Temporary unavailability detection</li>
<li>Mailbox existence checking</li>
<li>Catch-All testing</li>
<li>Greylisting detection</li>
</ul>
<p>We do not send any email to the recipient address during the entire validation process. All processing is done on our servers, your IP addresses and domains are not affected in any way by the Email-Validator service – absolutely no blacklisting risk for your IPs and domains.</p>
<h4>Data Protection and Privacy Policy</h4>
<p>Please see the Frequently Asked Questions section.</p>
<h4>Getting Started</h4>
<p>The plugin requires an API Key. Please sign up for an account at<br />
https://www.byteplant.com/email-validator/free-trial-registration.html (no credit card required).<br />
The trial account comes with 1,000 free credits.</p>


Byteplant Email Validator

With the Byteplant Email Validator plugin you can easily verify with a real-time live check if an email address really exists and is valid (https://ww …

dillilabs

<p>Add advanced email address validation using Dilli Email Validation API (DEVA). Prevent a site visitor from submitting a form with fake or incorrect email address on your site. No more lost leads due to mis-typed email addresses. No more wasting your precious time reading and responding to spam leads with incorrect email addresses. It hooks into the WordPress core function that is used by most form plugins to validate email address. As a result, it works with most forms.</p>
<p>Learn more about <a href="https://www.dillilabs.com/products/email-validation-api/" rel="nofollow ugc">Dilli Email Validation API</a>. This plugin requires an API Key which can be obtained for FREE by <a href="https://deva.dillilabs.com/register" rel="nofollow ugc">signing up here</a>.</p>
<h4>Known Compatible Forms</h4>
<ul>
<li>WordPress registration</li>
<li>Contact Form 7</li>
<li>Gravity Forms</li>
<li>Ninja Forms</li>
<li>Jetpack/Grunion contact forms</li>
<li>Any other forms that uses <code>is_email($email)</code> WordPress core function to validate email address field.</li>
</ul>
<h4>Available Languages</h4>
<ul>
<li>English</li>
<li>German (Deutsche)</li>
</ul>
<h4>Features</h4>
<ul>
<li>Validates email address format. Ex: email address <code>fooAtdillilabs.com</code> is invalid because of missing ‘@’</li>
<li>Checks for existence of MX records of the email address domain. Ex: <code>foobar@dlfkdlfkf.co</code> is invalid because no MX records exist for domain dlfkdlfkf.co.</li>
<li>Checks for Disposable/Temporary email addresses. Ex: user@mailinator.com is invalid because mailinator.com provides temporary shared temporary email inboxes.</li>
<li>Checks for conformity with ESP (Email Service Provider) grammar rules. Ex: <code>bob@yahoo.com</code> is invalid because Yahoo does not allow user part (<code>bob</code> in this case) to be less than 4 characters.</li>
<li>Checks for profanity in user part of email address. Ex: <code>f***you@gmail.com</code> is invalid.</li>
<li>Checks user and domain parts of an email address for known malicious patterns. Ex: <code>jondoe@gmail.com</code>, <code>foobar@yahoo.com</code>, <code>idontwanttogive@gmail.com</code> and <code>noemail@gmail.com</code> will be treated as invalid.</li>
<li>Checks email address domain against a known blacklist.</li>
<li>Checks email address against a known blacklist of frequently used email addresses for spam.</li>
<li>Checks for reserved domains. Ex: example.com is a reserved domain. Therefore, validemail@example.com is not allowed.</li>
<li>Checks for Role-based email addresses. Ex: info@someorganization.com will be treated as invalid.</li>
<li>Checks for safe domains. Restricts emails whose domains represents sites with adult content.</li>
<li>Checks for non-business email address.  Ex: *@gmail.com, *@yahoo.com, *@hotmail.com email addresses will be treated as invalid.</li>
<li>Add custom blocklist. You may request certain domains, emails and users to be blocked.</li>
</ul>


Dilli Email Validator

Using the free 100 validation took 5 minutes having 10 logins only on my site.
Each login (not registration! login!!!) used 5 validations. I see no sense in validating logins (well, it makes sense for the provider asking 0.5 cents per validation). Even my admin user's (already logged in) ajax calls were validated each time.

And the worst is that it blocked valid users logging in with an email address from free email providers (not disposable).


BIG waste of money

Validates email address in forms. Prevents form submission if email address is detected to be invalid thereby reducing spam and eliminating typos.

Byteplant Email Validator vs Dilli Email Validator