serverless-nodemailer-error.js

const nodemailer = require("nodemailer");

module.exports.handle = async (event, context, callback) => {
  console.log("Recieved Request started at " + new Date().getTime())

  const transporter = nodemailer.createTransport({
    host: "example.com",
    port: 25,
    secure: false, // true for 465, false for other ports
    auth: {
      user: "example-user@example.com", // generated ethereal user
      pass: "examplepassword", // generated ethereal password
    },
    requireTLS: true
  })

  const requestBody = JSON.parse(event.body);

  // Nodemailer usage
  // [Help link](https://nodemailer.com/about/)
  const sendMailData = {
    from: "sender@server.com",
    to: "receiver@sender.com",
    subject: "Message title",
    text: "Plaintext version of the message",
    html: "<p>HTML version of the message</p>"
  };

  async function wrapedSendMail(mailOptions) {
    return new Promise((resolve, reject) => {
      transporter.sendMail(mailOptions, function (error, info) {
        if (error) {
          console.log("error is " + error);
          resolve(false); // or use rejcet(false) but then you will have to handle errors
        }
        else {
          console.log('Email sent: ' + info.response);
          resolve(true);
        }
      })
    }
   )
  }

  let status = await wrapedSendMail(sendMailData);

  console.log("Recieved mail at " + new Date().getTime());
  const response = {
    statusCode: 200,
    body: status,
  };

  // either return cb(undefined, response) or return response
  return response;
};