Verify emails at WooCommerce checkout

The cost of a bad email in a WooCommerce store

In WooCommerce, the customer's email is the backbone of the whole post-purchase experience. Order confirmations, payment receipts, shipping and tracking updates, and account password resets all go to that one address. When it's mistyped, the customer thinks their order vanished and opens a support ticket — or disputes the charge. When it's a disposable inbox, you often can't reach them at all, and that pattern correlates strongly with promo abuse and card fraud.

WooCommerce validates email format at checkout but never confirms the mailbox is real. "buyer@gmial.com" and "temp@mailinator.com" both pass. Every one of those becomes a bounced transactional email, a reputation hit for your store's sending domain, and a support burden.

Verifly adds a live mailbox check to your checkout and registration flow. Hook it into a validation action so an obviously undeliverable address blocks or warns before the order completes, and a disposable one gets flagged for review — cutting both bounced order mail and the fraud that hides behind fake inboxes.

Add Verifly to WooCommerce checkout

1. Grab a free Verifly key at verifly.email/api/v1/autonomous/register — 100 credits, no card, no captcha.
2. In a small custom plugin or your theme's functions.php, hook woocommerce_after_checkout_validation (and optionally the registration hook).
3. Call Verifly's verify endpoint with the billing email server-side and read the result.
4. On undeliverable, add a checkout error so the customer fixes the address. On disposable, either block or tag the order for manual review.

add_action('woocommerce_after_checkout_validation', function ($data, $errors) {
  $email = $data['billing_email'];
  $url = 'https://verifly.email/api/v1/verify?email=' . urlencode($email);

  $res = wp_remote_get($url, [
    'headers' => ['Authorization' => 'Bearer vf_your_api_key'],
  ]);
  $body = json_decode(wp_remote_retrieve_body($res), true);

  if (($body['result'] ?? '') === 'undeliverable') {
    $errors->add('billing_email', 'This email address looks undeliverable. Please double-check it.');
  }
}, 10, 2);