static function sendEmail($to, $from, $subject, $body = false, $type = 'text/plain', $encoding = '8bit') {
      Env::useLibrary('swift');
      
      $mailer = self::getMailer();
      if(!($mailer instanceof Swift)) {
        throw new NotifierConnectionError();
      } // if

      // Bypass fancy mailer if using sendmail
      $mail_transport_config = config_option('mail_transport', self::MAIL_TRANSPORT_MAIL);
      if($mail_transport_config == self::MAIL_TRANSPORT_MAIL) {
        $headers =
          "From: $from\r\n".
          "Content-Type: $type; charset=\"{$mailer->charset}\"; format=flowed\r\n".
          "Content-Transfer-Encoding: $encoding\r\n";
        return mail($to, $subject, $body, $headers, "-r $from");
      }

      $result = $mailer->send($to, $from, $subject, $body, $type, $encoding);
      $mailer->close();
      
      return $result;
    } // sendEmail