Tushar Sharma

<p>Email OTP Login adds an additional layer of security to your WordPress site by requiring users to verify an OTP sent to their email after entering their username and password. This ensures that only users with access to the registered email can log in.</p>
<p>Features:</p>
<ul>
<li>Email OTP verification during <strong>login</strong>.</li>
<li>OTP expires in 5 minutes (configurable).</li>
<li>OTP stored securely using WordPress password hashing.</li>
<li>Works with the default WordPress login form.</li>
<li>Uses WordPress built-in <code>wp_mail()</code> function (works with SMTP plugins).</li>
</ul>
<p>This plugin does <strong>not modify WordPress core files</strong>.</p>
<h3>License</h3>
<p>This plugin is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2 or later.</p>
<p>This plugin is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.</p>


Email OTP Login

Adds OTP (One-Time Password) verification after login for enhanced security in WordPress. OTP is sent to the user's email.

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.

Email OTP Login vs Dilli Email Validator