rishav001

<p>Rishav AuthNova OTP adds a one-time-password verification layer to core WordPress authentication flows.</p>
<p>Features include:</p>
<ul>
<li>Configurable OTP length and charset (numeric or alphanumeric)</li>
<li>OTP expiry and retry limits with temporary lockouts</li>
<li>Login OTP verification step (after password check)</li>
<li>OTP-gated registration flow</li>
<li>OTP-gated password reset flow</li>
<li>Delivery via wp_mail, SendGrid, and Twilio</li>
<li>OTP storage using hashes (never plaintext)</li>
<li>Resend OTP with cooldown and challenge rotation</li>
</ul>
<p>Security highlights:</p>
<ul>
<li>OTP values are hashed before storage and are never saved as plaintext</li>
<li>OTP hashes use keyed HMAC storage and constant-time verification</li>
<li>OTP challenges expire automatically and enforce retry limits per challenge</li>
<li>Request throttling applies cooldown and exponential backoff per IP and identifier</li>
<li>Lockout windows reduce repeated invalid OTP submissions</li>
<li>Nonces are applied on sensitive form submissions</li>
<li>Public auth responses are intentionally generic to reduce account-enumeration leakage</li>
<li>Delivery uses synchronous-first send with bounded async retry fallback and challenge-level delivery status tracking</li>
</ul>
<p>Security limitations:</p>
<ul>
<li>This plugin does not replace passwords, HTTPS, WAF/rate-limiting at the edge, or secure hosting controls</li>
<li>OTP delivery depends on the configured email/SMS provider uptime and deliverability</li>
<li>Administrators should combine this plugin with standard WordPress hardening and monitoring</li>
</ul>
<p>Reliability notes:</p>
<ul>
<li>OTP delivery is attempted synchronously first to reduce silent failures</li>
<li>If synchronous delivery fails and background delivery is healthy, the plugin schedules bounded retries</li>
<li>If background delivery is unhealthy (for example DISABLE_WP_CRON), fallback queueing is skipped and users receive a retry-safe error</li>
<li>Resend cooldown state is server-authoritative and exposed through a status endpoint used by frontend countdown UX</li>
<li>Background queue payload contains only challenge ID (no raw OTP or destination data)</li>
</ul>
<h3>External Services</h3>
<p>This plugin can connect to third-party services to deliver OTP messages. These services are optional and only used if enabled in plugin settings.</p>
<h4>Twilio (SMS Delivery)</h4>
<ul>
<li>Service: Twilio Programmable Messaging API</li>
<li>Purpose: Send OTP codes by SMS</li>
<li>Data sent: destination phone number, sender phone number, OTP message text, account SID for authentication</li>
<li>Credential handling: Twilio credentials are stored in WordPress options and used only when sending OTP messages</li>
<li>When sent: when OTP delivery method includes SMS and an OTP is generated for login, registration, password reset, or resend</li>
<li>Why sent: to deliver time-sensitive OTP codes to the user by SMS</li>
<li>Terms of Service: https://www.twilio.com/legal/tos</li>
<li>Privacy Policy: https://www.twilio.com/en-us/legal/privacy</li>
</ul>
<h4>SendGrid (Email Delivery)</h4>
<ul>
<li>Service: SendGrid Mail Send API</li>
<li>Purpose: Send OTP codes by email</li>
<li>Data sent: recipient email address, sender email/name, message subject, OTP message body, API key for authentication</li>
<li>Credential handling: SendGrid API key is stored in WordPress options and used only when sending OTP messages</li>
<li>When sent: when email provider is set to SendGrid and an OTP is generated for login, registration, password reset, or resend</li>
<li>Why sent: to deliver time-sensitive OTP codes to the user by email</li>
<li>Terms of Service: https://sendgrid.com/policies/terms/</li>
<li>Privacy Policy: https://sendgrid.com/policies/privacy/</li>
</ul>
<h3>Configuration</h3>
<ol>
<li>Set OTP length, type, expiry, retry limit, and lockout duration.</li>
<li>Choose delivery method: Email, SMS, or Both.</li>
<li>Configure provider credentials for SendGrid and/or Twilio if needed.</li>
<li>Enable or disable OTP on login, registration, and password reset flows.</li>
</ol>


Rishav AuthNova OTP

OTP verification for WordPress login, registration, and password reset using email and SMS delivery.

dillilabs

<p>This plugin integrates with the Dilli Email Validation API (DEVA) to block fake or incorrectly formatted email addresses at form submission, ensuring higher-quality leads and significantly reducing spam.</p>
<p>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>. Learn more about Dilli Email Validation API <a href="https://www.dillilabs.com/products/email-validation-api/" rel="nofollow ugc">here</a>.</p>
<p>This plugin hooks directly into the WordPress core email validation function (<code>is_email()</code>), which is used by most major form plugins. That means it works out of the box with popular form builders like:</p>
<ul>
<li>Contact Form 7</li>
<li>WPForms</li>
<li>Gravity Forms</li>
<li>Ninja Forms</li>
<li>Jetpack/Grunion contact forms</li>
<li>WordPress registration forms</li>
<li>and many others.</li>
</ul>
<p>No need to modify your forms — just install and activate the plugin.</p>
<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>Checks the IP address of the user submitting the form against a known list of malicious IP addresses.</li>
<li>Add custom blocklist. You may request certain domains, emails and users to be blocked. </li>
</ul>
<h4>Available Languages</h4>
<ul>
<li>English</li>
<li>German (Deutsche)</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 addresses in real-time and blocks form submissions with invalid or fake emails. Reduce spam, fix typos, and capture quality leads.

Rishav AuthNova OTP vs Dilli Email Validator