Swift_TransportException Expected response code 250 but got code "550", with message "550 5.7.1 Mail contain spam content 204C610003B "

Question

What could be the problem?

I set up mail on my site but now this problem started to occur could this be blocked for my ip? so how can i solve the problem?

Swift_Transport_AbstractSmtpTransport::assertResponseCode
vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php:459

    protected function assertResponseCode($response, $wanted)

    {

        if (!$response) {

         [tag:   $this->throwException(new Swift_TransportException('Expected response code '.implode('/', $wanted).' but got an empty response'));

]        }

 

        list($code) = sscanf($response, '%3d');

        $valid = (empty($wanted) || \in_array($code, $wanted));

 

        if ($evt = $this->eventDispatcher->createResponseEvent($this, $response,

            $valid)) {

            $this->eventDispatcher->dispatchEvent($evt, 'responseReceived');

        }

 

        if (!$valid) {

            $this->throwException(new Swift_TransportException('Expected response code '.implode('/', $wanted).' but got code "'.$code.'", with message "'.$response.'"', $code));

        }

    }

 

    /** Get an entire multi-line response using its sequence number */

I solved the problem, I'm waiting for your help