Jesin A

<p>Most email validators look for an <code>@</code> and a <code>.</code>(dot) some go further and blacklist certain domain names. But Mailgun’s Advanced email validation service goes deeper and looks for the existence of the domain name, presence of a <a href="http://en.wikipedia.org/wiki/MX_record" rel="nofollow ugc">MX record</a> and the custom ESP(Email Service Provider) grammar.<br />
The grammar here is the rules defined by each email provider. For example, Yahoo Mail addresses can only contain letters, numbers, underscores, and one period.<br />
So <code>user.name.abc@yahoo.com</code> perfectly passes the <a href="https://codex.wordpress.org/Function_Reference/is_email" rel="nofollow ugc">is_email()</a> function but can never exist as it contains more than one period. Such addresses can’t escape Mailgun’s Email validation.</p>
<h4>Why use Mailgun’s email validation service?</h4>
<ul>
<li>Performs the usual email syntax check.</li>
<li>Checks the existence of the email domain. So <code>user@some-random-characters.com</code> can’t escape.</li>
<li>Checks if the email domain has a MX record. So <code>anything@example.com</code> is caught.</li>
<li>Checks if the username complies with the grammar of its ESP (Email Service provider). Eg Gmail doesn’t allow usernames less than 6 characters and hyphens so <code>small@gmail.com</code> and <code>hyphen-user@gmail.com</code> can’t get away.</li>
</ul>
<h4>Why use this plugin?</h4>
<ul>
<li>Integrates with the <a href="https://codex.wordpress.org/Function_Reference/is_email" rel="nofollow ugc">is_email()</a> function of WordPress. So it works seamlessly with Contact Form 7, Jetpack/Grunion contact forms, WordPress registration form and any form which uses the <code>is_email()</code> function.</li>
<li>Kicks spam before it is inserted into the database</li>
<li>Ensures that the commenting process is uninterrupted even if Mailgun suffers a <a href="http://status.mailgun.com" rel="nofollow ugc">downtime</a></li>
<li>Works completely transparent, nothing changes in the frontend</li>
</ul>
<p>This plugin requires a Mailgun Public API Key which can be obtained by <a href="https://mailgun.com/signup" rel="nofollow ugc">signing up at Mailgun</a>.</p>
<p>If you’re trying out this plugin on a local WAMP/LAMP/MAMP installation make sure your system is connected to the Internet for this plugin to contact Mailgun.</p>
<h4>Available Languages</h4>
<ul>
<li>English</li>
<li>Serbo-Croatian by <a href="http://www.webhostinghub.com/" rel="nofollow ugc">Borisa Djuraskovic</a></li>
<li>Spanish by <a href="http://www.webhostinghub.com/" rel="nofollow ugc">Andrew Kurtis</a></li>
</ul>
<h4>Further Reading</h4>
<p>Read about Mailgun’s email validation service.</p>
<ul>
<li><a href="http://blog.mailgun.com/post/free-email-validation-api-for-web-forms/" rel="nofollow ugc">http://blog.mailgun.com/post/free-email-validation-api-for-web-forms/</a></li>
<li><a href="http://blog.mailgun.com/post/weekly-product-update-improvements-to-email-validation-api/" rel="nofollow ugc">http://blog.mailgun.com/post/weekly-product-update-improvements-to-email-validation-api/</a></li>
<li><a href="http://mailgun.github.io/validator-demo/" rel="nofollow ugc">Mailgun Address Validator demo</a> and its <a href="https://github.com/mailgun/validator-demo/tree/gh-pages" rel="nofollow ugc">source code</a></li>
<li>The <a href="https://websistent.com/wordpress-plugins/mailgun-email-validator/" rel="nofollow ugc">Mailgun Email Validator Plugin</a> official homepage.</li>
</ul>


Mailgun Email Validator

Implementing this plugin is straight forward and simple.

Works perfectly

Kick spam with a highly advanced email validation in comment forms, user registration and contact forms using Mailgun's Email validation service.

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.

Mailgun Email Validator vs Dilli Email Validator