public function clearRecipientHeaders()
    {
        $headers = $this->swiftMessage->getHeaders();

        foreach ($headers->getAll() as $header) {
            if (!$header instanceof Swift_Mime_Headers_MailboxHeader) {
                continue;
            }
            if (in_array(strtolower($header->getFieldName()), $this->recipientHeaderNames)) {
                $headers->removeAll($header->getFieldName());
            }
        }

        return true;
    }