diff --git a/lib/Subscribers/ConfirmationEmailMailer.php b/lib/Subscribers/ConfirmationEmailMailer.php
index 4186d86545..ada8aa188e 100644
--- a/lib/Subscribers/ConfirmationEmailMailer.php
+++ b/lib/Subscribers/ConfirmationEmailMailer.php
@@ -6,6 +6,7 @@ use Html2Text\Html2Text;
 use MailPoet\Mailer\Mailer;
 use MailPoet\Mailer\MailerError;
 use MailPoet\Models\Subscriber;
+use MailPoet\Services\Bridge;
 use MailPoet\Settings\SettingsController;
 use MailPoet\Subscription\Url;
 use MailPoet\Util\Helpers;
@@ -52,6 +53,12 @@ class ConfirmationEmailMailer {
       return false;
     }
 
+    $authorization_emails_validation = $this->settings->get(Bridge::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING_NAME);
+    $unauthorized_confirmation_email = isset($authorization_emails_validation['invalid_confirmation_address']);
+    if (Bridge::isMPSendingServiceEnabled() && $unauthorized_confirmation_email) {
+      return false;
+    }
+
     $segments = $subscriber->segments()->findMany();
     $segment_names = array_map(function($segment) {
       return $segment->name;
diff --git a/tests/integration/Subscribers/ConfirmationEmailMailerTest.php b/tests/integration/Subscribers/ConfirmationEmailMailerTest.php
index 7da8eee5e7..e6814f7a6e 100644
--- a/tests/integration/Subscribers/ConfirmationEmailMailerTest.php
+++ b/tests/integration/Subscribers/ConfirmationEmailMailerTest.php
@@ -8,6 +8,8 @@ use MailPoet\Mailer\Mailer;
 use MailPoet\Models\Segment;
 use MailPoet\Models\Subscriber;
 use MailPoet\Models\SubscriberSegment;
+use MailPoet\Services\Bridge;
+use MailPoet\Settings\SettingsController;
 use MailPoet\WP\Functions as WPFunctions;
 
 class ConfirmationEmailMailerTest extends \MailPoetTest {
@@ -69,6 +71,28 @@ class ConfirmationEmailMailerTest extends \MailPoetTest {
     expect($subscriber->getErrors()[0])->equals('send error');
   }
 
+  function testItDoesntSendWhenMSSIsActiveAndConfirmationEmailIsNotAuthorized() {
+    $subscriber = Subscriber::create();
+    $subscriber->hydrate([
+      'first_name' => 'John',
+      'last_name' => 'Mailer',
+      'email' => 'john@mailpoet.com'
+    ]);
+
+    $mailer = $this->makeEmpty(Mailer::class, [
+      'send' => Stub\Expected::never(),
+    ]);
+
+    $settings = new SettingsController;
+    $settings->set(Bridge::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING_NAME, ['invalid_confirmation_address' => 'email@email.com']);
+    $settings->set(Mailer::MAILER_CONFIG_SETTING_NAME, ['method' => Mailer::METHOD_MAILPOET]);
+    $sender = new ConfirmationEmailMailer($mailer);
+
+    $result = $sender->sendConfirmationEmail($subscriber);
+    expect($result)->equals(false);
+    $settings->set(Bridge::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING_NAME, null);
+  }
+
   function testItLimitsNumberOfConfirmationEmailsForNotLoggedInUser() {
     wp_set_current_user(0);
     expect((new WPFunctions)->isUserLoggedIn())->false();