# How to Send Emails for Free Using Nodemailer and Gmail SMTP

Sending emails for marketing campaigns, OTP verification, or customer support can sometimes be expensive. If you're looking for a way to send emails without spending a dime, you're in the right place.

In this tutorial, we'll walk through exactly how to set up free email sending using **Nodemailer** as our SMTP client and **Gmail** as our mail provider. That said, the core concepts apply to any SMTP client or email provider of your choice.

* * *

## Understanding the Basics: Key Email Terminology

Before we write a single line of code, let's get familiar with a few terms you'll encounter when working with email infrastructure.

### What is SMTP?

**SMTP** stands for **Simple Mail Transfer Protocol**. Think of it as the shared language that mail clients and mail servers use to communicate. Just like two people need a common language to understand each other, a mail client and mail server need SMTP to exchange messages.

We won't go deep into the internals of the protocol, but there are a handful of key concepts worth understanding.

* * *

### SMTP Host

The **SMTP host** is the email server responsible for sending, receiving, and relaying outgoing emails between the sender and recipient. For Gmail, this is `smtp.gmail.com`.

* * *

### SMTP Port

The **SMTP port** is the specific entry point on a server where the SMTP protocol operates. Different ports serve different purposes:

| Port | Protocol | Description |
| --- | --- | --- |
| **587** | STARTTLS | Upgrades a plain-text connection to an encrypted one over the same port. Recommended for most use cases. |
| **465** | SSL/TLS | Sends email over a fully encrypted connection from the start. |
| **25** | None | The original, unencrypted SMTP port. |
| **2525** | STARTTLS | An unofficial backup port, useful when 587 is blocked. |

* * *

### SMTP User

Your **SMTP username** is simply your email address (e.g., `you@gmail.com`). It's used to authenticate your application with the mail server.

* * *

### SMTP Password

Your **SMTP password** is used alongside your username for authentication. For Gmail, this won't be your regular account password. We'll cover exactly what to use in the setup section below.

* * *

## Setting Up Gmail for SMTP Authentication

Gmail doesn't allow you to authenticate with your regular account password when sending emails programmatically. Instead, you'll need to generate an **App Password**, which is a separate credential specifically for your application.

### Step 1: Enable Two-Factor Authentication

Before you can create an App Password, 2FA must be active on your Google account.

![](https://cdn.hashnode.com/uploads/covers/668dcfff41a19ff2eb4906bb/19d9c5b3-ee59-47f5-a555-afb595ae39bc.png align="center")

1.  Go to your [Google Account Security Settings](https://myaccount.google.com/security)
    
2.  Under **"How you sign in to Google"**, enable **2-Step Verification**
    

### Step 2: Generate an App Password

![](https://cdn.hashnode.com/uploads/covers/668dcfff41a19ff2eb4906bb/9f5d92be-45bf-4d35-bb75-c5fd60eee8b2.png align="center")

1.  Visit [Google App Passwords](https://myaccount.google.com/apppasswords)
    
2.  Enter your preferred app name
    
3.  Click **Create** and **copy the password**. You'll only see it once.
    

> ⚠️ **Keep this password safe.** Store it in your `.env` file and never commit it to version control.

* * *

## Installing Nodemailer

Install Nodemailer via npm:

```plaintext
npm install nodemailer
```

* * *

## Configuring Environment Variables

Create a `.env` file in your project root and add the following:

```env
SMTP_HOST=smtp.gmail.com
SMTP_PORT=465
SMTP_SECURE=true
SMTP_USER=your-email@gmail.com
SMTP_PASS=your-app-password
```

> **Note on ports:** Use port `465` with `SMTP_SECURE=true` for SSL/TLS. Use port `587` with `SMTP_SECURE=false` for STARTTLS.

* * *

## Creating the Nodemailer Transporter

The **transporter** is the core object in Nodemailer. It manages the connection to your email provider and handles sending messages.

```javascript
import nodemailer from "nodemailer";

const transporter = nodemailer.createTransport({
  host: process.env.SMTP_HOST,
  port: Number(process.env.SMTP_PORT),
  secure: process.env.SMTP_SECURE === "true", // true for port 465, false for 587
  auth: {
    user: process.env.SMTP_USER,
    pass: process.env.SMTP_PASS,
  },
});
```

* * *

## Sending an Email

With your transporter configured, sending an email is straightforward:

```javascript
await transporter.sendMail({
  from: `"Your Name" <${process.env.SMTP_USER}>`,
  to: "recipient@example.com",
  subject: "Hello from Nodemailer!",
  text: "This is a plain text email.",
  html: "<p>This is an <strong>HTML</strong> email.</p>",
});
```

That's it. You're now sending emails for free using Gmail's SMTP server.

* * *

## Putting It All Together

Here's a complete, reusable `sendEmail` utility function:

```javascript
import nodemailer from "nodemailer";

const transporter = nodemailer.createTransport({
  host: process.env.SMTP_HOST,
  port: Number(process.env.SMTP_PORT),
  secure: process.env.SMTP_SECURE === "true",
  auth: {
    user: process.env.SMTP_USER,
    pass: process.env.SMTP_PASS,
  },
});

export async function sendEmail({ to, subject, text, html }) {
  return await transporter.sendMail({
    from: `"My App" <${process.env.SMTP_USER}>`,
    to,
    subject,
    text,
    html,
  });
}
```

* * *

## Conclusion

In this guide, we covered:

*   The core SMTP concepts you need to know (host, port, credentials)
    
*   How to set up Gmail with an App Password for secure programmatic access
    
*   How to configure Nodemailer and send your first email
    

Gmail's free SMTP tier is a great starting point for low-to-medium volume sending. As your application scales, you may want to explore dedicated transactional email services like **Resend**, **Mailgun**, or **SendGrid**. For getting started without spending anything, though, this setup is hard to beat.

Happy sending!