nodemailer

Nodemailer Library: Sending Email in JavaScript (Node.js)

Nodemailer is the most popular module for sending emails from Node.js applications. It provides a simple yet powerful API for working with various email services (SMTP, Gmail, Outlook, SendGrid, Amazon SES, etc.). The library supports HTML templates, attachments, data streams, and encryption (SSL/TLS).

Why is Nodemailer needed?

In modern web development, sending email is a basic functionality: registration letters, password reset, notifications, newsletters. Nodemailer solves the following tasks:

• Universal work with any SMTP server.
• Support for HTML and text messages.
• Attached files (images, PDFs, archives).
• Streaming large data.
• Integration with popular services (Gmail, Yandex, Mail.ru).

Installation

Install the module via npm:

npm install nodemailer

For TypeScript additionally:

npm install @types/nodemailer

Main Functions

• createTransport() — creating a transport to connect to the mail server.
• sendMail() — sending an email with settings (from, to, subject, body, attachments).
• verify() — verifying the connection to the server.
• use() — connecting plugins (e.g., for templating).

Code Example in Node.js

const nodemailer = require('nodemailer');

// Setting up transport (example for Gmail with App Password)const transporter = nodemailer.createTransport({  service: 'gmail',  auth: {    user: 'your-email@gmail.com',    pass: 'your-app-password' // Not a regular password, but an app password  }});

// Function to send emailasync function sendEmail() {  try {    const info = await transporter.sendMail({      from: '"Your Name" <your-email@gmail.com>',      to: 'recipient@example.com',      subject: 'Hello from Node.js!',      html: '<h1>Test Email</h1><p>Sent via Nodemailer.</p>'    });    console.log('Message sent: %s', info.messageId);  } catch (error) {    console.error('Error sending:', error);  }}

sendEmail();

When to use Nodemailer?

• Registration and Authorization — sending email confirmation letters.
• Notifications — alerts about user actions (order, comment).
• Newsletters — mass sending (but for large volumes it's better to use SendGrid/Mailgun).
• Debugging — sending emails in a local environment (via Ethereal or Mailtrap).

Important: For production, use real SMTP servers (SendGrid, Amazon SES, Mailgun) or configure your own mail server. Gmail has limits (500 emails/day) and requires an app password.

Nodemailer is the de facto standard for sending email in Node.js. It is simple, reliable, and has a large community.