Email Validation for E-commerce:
The Hidden Revenue Multiplier

// Add to your checkout.liquid
<script>
  document.addEventListener('DOMContentLoaded', function() {
    const emailInput = document.querySelector('#checkout_email');

    emailInput.addEventListener('blur', async function() {
      const params = new URLSearchParams({
        email: this.value,
        verifyMx: true,
        verifySmtp: true,
        detectName: false
      });

      const response = await fetch('https://api.email-check.app/v1-get-email-details?' + params, {
        headers: {
          'accept': 'application/json',
          'x-api-key': 'YOUR_API_KEY'
        }
      });

      const result = await response.json();
      if (!result.validFormat || !result.validMx || !result.validSmtp) {
        this.setCustomValidity('Please enter a valid email address');
      }
    });
  });
</script>

// Add to your functions.php
add_action('woocommerce_checkout_process', 'validate_checkout_email');
function validate_checkout_email() {
    $email = $_POST['billing_email'];
    $params = [
        'email' => $email,
        'verifyMx' => 'true',
        'verifySmtp' => 'true',
        'detectName' => 'true',
        'suggestDomain' => 'true',
        'checkDomainAge' => 'true',
        'checkDomainRegistration' => 'true'
    ];

    $validation = wp_remote_get('https://api.email-check.app/v1-get-email-details?' . http_build_query($params), [
        'headers' => [
            'accept' => 'application/json',
            'x-api-key' => 'YOUR_API_KEY'
        ]
    ]);

    if (!is_wp_error($validation)) {
        $result = json_decode(wp_remote_retrieve_body($validation));
        if (!$result->validFormat || !$result->validMx || !$result->validSmtp) {
            wc_add_notice('Please enter a valid email address', 'error');
        }
    }
}