Email Sending System using NodeJS

Sending emails programmatically is a common requirement in many applications, especially for user notifications, order confirmations, password resets, and newsletters.

Features of Email App

Create a simple application that allows you to send emails using NodeJS. The application will feature:

• Sending plain text and HTML emails.
• Sending emails with attachments.
• Customizing the sender, recipient, subject, and body of the email.

Approach

Below are the steps to follow for building an email-sending system using NodeJS

• Install Nodemailer: Nodemailer is the main module we will use to send emails.
• Create an Email Sending Route: Define a route to handle the email-sending process.
• Set Up SMTP Service: We'll use an SMTP (Simple Mail Transfer Protocol) service for sending emails.
• Handle Email Input: Capture user input (like recipient, subject, and message) using the body parser.
• Send the Email: Use Nodemailer to send the email.

Steps to Build the Email Sending System

Build the email sender by following these steps:

Step 1: Create a Project Folder

Open your terminal (Command Prompt/PowerShell) and run the following commands

mkdir email-sending-system
cd email-sending-system

Step 2: Initialize a NodeJS Project

Run the following command to create a package.json file

npm init -y

Step 3: Install Dependencies

Run the following command to install the required dependencies

npm install express nodemailer body-parser

This installs

• Express: Backend framework to handle routing.
• Nodemailer: Module for sending emails.
• Body-parser: Middleware to handle form submissions.

Step 4: Create Server File

Create a file named app.js and require the necessary modules. Then, create an Express instance and set up body-parser to capture form data.

const express = require('express');
const nodemailer = require('nodemailer');
const bodyParser = require('body-parser');
const app = express();
const PORT = 3000;

app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());

app.set('view engine', 'ejs');

app.get('/', (req, res) => {
    res.render('home');
});

// Handle email sending
app.post('/send-email', (req, res) => {
    const { recipient, subject, message } = req.body;

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

    // Define the email options
    const mailOptions = {
        from: 'sender mail', 
        to: recipient, 
        subject: subject, 
        text: message,
    };

    // Send the email
    transporter.sendMail(mailOptions, (error, info) => {
        if (error) {
            console.error("Error occurred:", error);
            res.status(500).send('Error in sending email. Please try again later.');
        } else {
            console.log('Email sent:', info.response);
            res.send('Email sent successfully!');
        }
    });
});

app.listen(PORT, () => {
    console.log(`App is running on port ${PORT}`);
});

• Express Setup: Uses Express to handle HTTP requests and route them.
• Nodemailer: Sends emails via Nodemailer using Gmail's SMTP service.
• Body-Parser Middleware: Body-parser parses form data from POST requests.
• EJS for Dynamic Pages: EJS is used to render HTML templates dynamically with form input.
• Form Submission and Error Handling: Manages form data, sends emails, and displays success or error messages.

Step 5: Enable an App Password in Gmail

• Enable 2-Step Verification (2FA) in your Google Account settings.
• Go to Security > App Passwords and sign in if prompted.
• Select Other (Custom name) and enter a name (e.g., NodeMailer App).
• Google generates a 16-character App Password.
• Copy and use this password in your Node.js application.

const transporter = nodemailer.createTransport({
    service: 'gmail',
    auth: {
        user: 'your-email@gmail.com',
        pass: 'your-app-password'
    }
});

Step 6: Create the Home Page (home.ejs)

Create a views folder in your root directory, and inside it, create a file called home.ejs. Inside views/home.ejs, add the following code

<html>
<body>
    <h1>Send Email</h1>
    <form action="/send-email" method="POST">
        <label for="recipient">Recipient:</label>
        <input type="email" name="recipient" id="recipient" required><br>

        <label for="subject">Subject:</label>
        <input type="text" name="subject" id="subject" required><br>

        <label for="message">Message:</label><br>
        <textarea name="message" id="message" rows="5" cols="50" required></textarea><br>

        <button type="submit">Send Email</button>
    </form>
</body>

</html>

Output:

node app.js