Node Email Code Confirmation

2020, May 06

This method is commonly used by some websites like Twitter, Github, Colors and others.This method is used for verifying email addresses for authentication.

Steps and Setup

  1. Create a new folder node-email-code-verification
  2. Open the folder in terminal
  3. Create a server.js file
  4. Create a mail.js file for sending email
  5. Create a user.jsfile for storing some values like email password, etc
  6. Create an index.html file which holds the main content where user inputs their email for confirmation
  7. Create a confirm.html file where user input their confirmation code gotten from the email message
  8. Create a success.html file which will be rendered if the confirmation is successfull
  9. Initialize a new project by running npm init -y
  10. Install the required dependencies by running npm i --save express nodemailer

Setting Up the mailer (mail.js)

create a new const that holds a variable to your mail function which will be exported

const nodemailer = require('nodemailer');

const user = require('./user')

const mail = (email, message) => {
    var transporter = nodemailer.createTransport({
        service: 'gmail',
        auth: {
            user: user.mail,
            pass: user.auth

    var mailOptions = {
        from: user.mail,
        to: email,
        subject: 'EMAIL CONFIRMATION',
        text: `Confirmation Pins is ${message}`

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

module.exports = mail;

After the mail.js setup successfully, you can close it and set up the configuration file (user.js)

const user = {
    mail: '',       //gmail account
    auth: ''      //account password

module.exports = user;

Server.js setup

Lets setup our server.js file for the installed dependencies.
We have to require some dependencies in order for our backend to run because our application is fully backend dependent;

const express = require('express');
const path = require('path');

const mail = require('./mail');

const server = express();

server.use(express.urlencoded({ extended: false }));

We required some packages

  • Express: For our backend application
  • path: To use our static files which are index.html, confirm.html, and success.html
  • mail: To use our exported function in mail.js
  • Line 5 allow us to use static files which may comtains all css files and images
  • Line 6 and 7 allows us to read request from the url provided

We now have to render the index.html file for the client in order for him/her to enter their email address. This is also from the server.js

server.get('/', (req, res) => {
    res.sendFile(path.join(__dirname, 'index.html'));

After the mail.js and user.js file is set up successfully, add a form to your index.html file which takes an input of email and makes a POST request to the home route '/' We can now handle the post request in our backeend in server.js file

let code;'/', (req, res) => {
    code = Math.floor(Math.random() * 903192)
    res.sendFile(path.join(__dirname, 'confirm.html'));
    mail(, code)

A code variable was initialized. When the user makes a post request to the home route, a new code is generated which is now sent to the client's mail with the mail function we imported above;.

Thats the End of the Sending Part
Now we add a form with an input of tel which makes a post request to the '/confirmEmail' route to verify the code sent'/confirmEmail', (req, res) => {
    if (req.body.code == code) {
        res.sendFile(path.join(__dirname, 'success.html'))
    } else {
        res.sendFile(path.join(__dirname, 'index.html'))

This checks if the code tested by the user is equal to the code sent, if the response is true, the success.html page is rendered, if error, the index page is rendered for the user to start allover. If success, you can add the user to your registered members in your database and render the success page


We've been writing code since but we didn't run it, so we have to create a port to start our server in our server.js file

const port = process.env.PORT || 5500
server.listen(port, () => console.log(`Server started on port ${port}`))

Start Your Server

We can now test our application by runing node server.js in the terminal we opened

The Whole Code can be found in my Github Repo Here