index.js

var express=require('express');
var nodemailer = require("nodemailer");
var app=express();
/*
    Here we are configuring our SMTP Server details.
    STMP is mail server which is responsible for sending and recieving email.
*/
var smtpTransport = nodemailer.createTransport("SMTP",{
    service: "Gmail",
    auth: {
        user: "aroy0761@gmail.com", //this is a test email.
        pass: "sayankarmakar"
    }
});
var rand,mailOptions,host,link;
/*------------------SMTP Over-----------------------------*/

/*------------------Routing Started ------------------------*/

app.get('/',function(req,res){
    res.sendfile('index.html');
});
app.get('/send',function(req,res){
        rand=Math.floor((Math.random() * 100) + 54);
    host=req.get('host');
    link="http://"+req.get('host')+"/verify?id="+rand;
    mailOptions={
        to : "akashkarmakar787@gmail.com",
        subject : "Please confirm your Email account",
        html : "Hello,<br> Please Click on the link to verify your email.<br><a href="+link+">Click here to verify</a>" 
    };
    console.log(mailOptions);
    smtpTransport.sendMail(mailOptions, function(error, response){
     if(error){
            console.log(error);
        res.end("error");
     }else{
            console.log("Message sent: " + response.message);
        res.end("sent");
         }
});
});
app.listen(3000,function(){
    console.log("Express Started on Port 3000");
});