code: public function sendNow()
      {
          $config = $this->getManager()->getDI()->getConfig();
          $message = $this->getMessage();
  
          $username = $config->email->username;
          $password = $config->email->password;
          $host = $config->email->host;
          $port = $config->email->port;
  
          $transport = \Swift_SmtpTransport::newInstance($host, $port);
  
          $transport->setUsername($username);
          $transport->setPassword($password);
  
          $swift = \Swift_Mailer::newInstance($transport);
  
          $failures = [];
  
          $swift->send($message, $failures);
      }
docs: Send message instantly, without a queue
  
  @return void