app.intent('sendMail', (conv, params) => {
      const nodemailer = require('nodemailer');
      const transporter = nodemailer.createTransport({
        service: 'gmail',
        auth: {
          user: 'youremail@gmail.com',
          pass: 'yourPassword'
        }
      });

      var mailOptions = {
        from: 'youremail@gmail.com',
        to: email, //receiver email
        subject: 'Mail subject',
        text: 'mail body'
      };

      transporter.sendMail(mailOptions, function (error, info) {
        if (error) {
          console.log(error);
        } else {
          console.log('Email sent: ' + info.response);
        }
      });


});