Introduction to Email in NodeJS

Email is one of the most popular forms of communication in the digital age. Many online applications require the ability to send and receive emails. NodeJS offers a variety of alternatives for delivering emails.

In this post, we’ll look at how to send email in NodeJS using several modules, including the built-in ‘nodemailer‘ module.

Sending emails

NodeJS has a number of modules for sending emails. The built-in ‘nodemailer’ module, on the other hand, is one of the most popular and commonly used modules. This module is simple to set up and use, and it includes a number of complex capabilities such as attachments, HTML content, and more.

Here is a basic example of sending an email using the ‘nodemailer’ module:

const nodemailer = require('nodemailer');

// create reusable transporter object using the default SMTP transport
const transporter = nodemailer.createTransport({
  host: 'smtp.example.com',
  port: 587,
  secure: false, // true for 465, false for other ports
  auth: {
    user: 'username@example.com',
    pass: 'userpassword'
  }
});

// setup email data with unicode symbols
const mailOptions = {
  from: '"Fred Foo 👻" <foo@example.com>', // sender address
  to: 'bar@example.com, baz@example.com', // list of receivers
  subject: 'Hello ✔', // Subject line
  text: 'Hello world?', // plain text body
  html: '<b>Hello world?</b>' // html body
};

// send mail with defined transport object
transporter.sendMail(mailOptions, (error, info) => {
  if (error) {
    return console.log(error);
  }
  console.log('Message sent: %s', info.messageId);
  console.log('Preview URL: %s', nodemailer.getTestMessageUrl(info));
});

Explanation:

The ‘nodemailer’ module is required in the first step.
Then, using the default SMTP transport, we construct a transporter object and configure it with our email host and authentication information.
Then we define email choices such the sender, recipients, topic, and message text.
Finally, to send the email, we use the sendMail() method.

Q&A

Q: What is the ‘nodemailer’ module in NodeJS?
A: The ‘nodemailer’ module is a popular and widely used NodeJS module for sending emails. It provides advanced features, such as attachments, HTML content, and more.

Q: How do I send an email?
A: To send an email using NodeJS, you need to install and use a module, such as the built-in ‘nodemailer’ module. You can use the module to create a transporter object, configure it with your email host and authentication details, and then send the email using the sendMail() function.

Exercises

Write a program to send a basic email from your NodeJS application.
Write a program to receive emails from a specific email address using NodeJS.
Write a program to send an HTML formatted email using NodeJS.

Answers

Here is an example of sending a basic email using NodeJS:

const nodemailer = require('nodemailer');

let transporter = nodemailer.createTransport({
    host: 'smtp.gmail.com',
    port: 587,
    secure: false,
    auth: {
        user: 'youremail@gmail.com',
        pass: 'yourpassword'
    }
});

let mailOptions = {
    from: 'youremail@gmail.com',
    to: 'recipientemail@gmail.com',
    subject: 'Subject of the Email',
    text: 'Hello, this is a test email sent from NodeJS.'
};

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

Here is an example of receiving emails using NodeJS:

const imap = require('imap');
const simpleParser = require('mailparser').simpleParser;

let imapConfig = {
    user: 'youremail@gmail.com',
    password: 'yourpassword',
    host: 'imap.gmail.com',
    port: 993,
    tls: true
};

let imapConnection = new imap(imapConfig);

imapConnection.once('ready', function() {
    imapConnection.openBox('INBOX', true, function(error, box) {
        if (error) throw error;
        let searchCriteria = ['UNSEEN'];
        let fetchOptions = {
            bodies: ['HEADER', 'TEXT'],
            markSeen: true
        };
        imapConnection.search(searchCriteria, fetchOptions, function(error, messages) {
            if (error) throw error;
            messages.forEach(function(message) {
                simpleParser(message.parts[1].body, function(error, email) {
                    console.log(email.text);
                });
            });
        });
    });
});

imapConnection.connect();

Here is an example of sending an HTML formatted email using NodeJS:

var nodemailer = require('nodemailer');

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

var mailOptions = {
  from: 'youremail@gmail.com',
  to: 'recipient1@example.com, recipient2@example.com, recipient3@example.com',
  subject: 'Sending Email using Node.js',
  text: 'That was easy!'
};

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

In this answer above, we are sending the same email to three recipients recipient1@example.com, recipient2@example.com, and recipient3@example.com. The nodemailer library will handle the process of sending an email to multiple recipients.

Also watch the above video on Youtube