diff --git a/src/Hermes/SendEmailHandler.php b/src/Hermes/SendEmailHandler.php
index af32b35..7d420a7 100644
--- a/src/Hermes/SendEmailHandler.php
+++ b/src/Hermes/SendEmailHandler.php
@@ -3,9 +3,12 @@
 namespace Crm\RempMailerModule\Hermes;
 
 use Crm\RempMailerModule\Models\Api\Client;
+use Nette\Utils\Validators;
 use Tomaj\Hermes\Handler\HandlerInterface;
 use Tomaj\Hermes\Handler\RetryTrait;
 use Tomaj\Hermes\MessageInterface;
+use Tracy\Debugger;
+use Tracy\ILogger;
 
 class SendEmailHandler implements HandlerInterface
 {
@@ -22,6 +25,11 @@ public function handle(MessageInterface $message): bool
     {
         $payload = $message->getPayload();
 
+        if (!Validators::isEmail($payload['email'])) {
+            Debugger::log('Attempt to send email through REMP Mailer with invalid email address: ' . $payload['email'], ILogger::WARNING);
+            return false;
+        }
+
         $this->apiClient->sendEmail(
             $payload['email'],
             $payload['mail_template_code'],