code: public static function getTransport($host, $port, $encryption, $username, $password)
      {
          if (empty($host)) {
              throw new InternalServerErrorException("Missing SMTP host. Check service configuration.");
          }
          if (empty($port)) {
              throw new InternalServerErrorException("Missing SMTP port. Check service configuration.");
          }
          $transport = new SmtpTransport($host, $port);
  
          if (!empty($encryption)) {
              $transport->setEncryption($encryption);
          }
  
          if (!empty($username) && !empty($password)) {
              $transport->setUsername($username);
              $transport->setPassword($password);
          }
  
          return $transport;
      }
docs: @param $host
  @param $port
  @param $encryption
  @param $username
  @param $password
  
  @return \Swift_SmtpTransport
  @throws \DreamFactory\Core\Exceptions\InternalServerErrorException