Code for sending the verification emails in node js using the nodemailer and uuid library. This script exports the sendVerificationEmail method that takes two parameters email address and callback for the response to the calling agent.

email.js

var nodemailer = require('nodemailer');
const uuid = require('uuid');

var transporter = nodemailer.createTransport({
  service : 'gmail',
  auth : {
    user : '',
    pass : ''
  }
});

function sendVerificationEmail(emailAddress,callback){
  const uuidv1 = require('uuid/v1');
  var v = uuidv1();
  var arr = v.split("-");
  var mailOptions = {
    from : '',
    to : emailAddress,
    subject : 'Company Name - Email Verification',
    text : 'Please verify your account using this code ' + arr[0]
  };
  transporter.sendMail(mailOptions, function(error, info){
    if (error) {
      console.log(error);
      return callback(true);
    } else {
      console.log(info);
      return callback(false,arr[0]);
    }
  });
}

module.exports = {sendVerificationEmail};