Node.js Email

In Node.js, sending emails is simple and efficient with the help of the Nodemailer package.

Why Use Node.js for Sending Emails?

Node.js is a powerful backend framework that simplifies handling asynchronous tasks like sending emails. It ensures that the email-sending process doesn’t block other parts of your application, making it fast and efficient.

Tool for Sending Emails in Node.js: Nodemailer

Nodemailer is the most popular package for sending emails in Node.js. It supports:

1. Sending plain text and HTML emails.
2. Adding attachments to emails.
3. Authentication with popular email services (e.g., Gmail, Outlook).

Setting Up the Project

Step 1: Create a New Node.js Project

Initialize a new project:

npm init -y

Install Nodemailer:

npm install nodemailer

Step 2: Import Nodemailer

Add the following line to your script:

const nodemailer = require('nodemailer');

Sending a Basic Email

Step 3: Configure the Email Transporter

The transporter is used to connect to your email service. You can use services like Gmail, Outlook, or a custom SMTP server.

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

Step 4: Define the Email Options

Email options include the recipient’s address, subject, and body of the email.

const mailOptions = {
    from: 'your-email@gmail.com', // Sender's email
    to: 'recipient-email@gmail.com', // Receiver's email
    subject: 'Welcome to Node.js Email Tutorial!',
    text: 'This is a simple text email sent from Node.js.', // Plain text body
};

Step 5: Send the Email

Use the sendMail() method to send the email:

transporter.sendMail(mailOptions, (err, info) => {
    if (err) {
        console.error('Error sending email:', err);
    } else {
        console.log('Email sent successfully:', info.response);
    }
});

Sending an HTML Email

You can send more visually appealing emails by using HTML content.

Example: Sending an HTML Email

const htmlMailOptions = {
    from: 'your-email@gmail.com',
    to: 'recipient-email@gmail.com',
    subject: 'HTML Email from Node.js',
    html: `
        <h1>Welcome to Node.js Email Tutorial!</h1>
        <p>This is an email sent with HTML content.</p>
    `,
};

transporter.sendMail(htmlMailOptions, (err, info) => {
    if (err) {
        console.error('Error sending email:', err);
    } else {
        console.log('HTML email sent successfully:', info.response);
    }
});

Adding Attachments

You can attach files to your emails using the attachments property.

Example: Sending an Email with Attachments

const attachmentMailOptions = {
    from: 'your-email@gmail.com',
    to: 'recipient-email@gmail.com',
    subject: 'Email with Attachment',
    text: 'Please find the attached file.',
    attachments: [
        {
            filename: 'example.txt', // File name
            path: './example.txt', // File path
        },
    ],
};

transporter.sendMail(attachmentMailOptions, (err, info) => {
    if (err) {
        console.error('Error sending email:', err);
    } else {
        console.log('Email with attachment sent successfully:', info.response);
    }
});

Using Environment Variables for Security

It’s not a good practice to hard-code your email credentials in the script. Instead, use environment variables.

Install the dotenv package:

npm install dotenv

Create a .env file in your project directory and add your credentials:

EMAIL=your-email@gmail.com
PASSWORD=your-email-password

Load the environment variables in your script:

require('dotenv').config();

const transporter = nodemailer.createTransport({
    service: 'gmail',
    auth: {
        user: process.env.EMAIL,
        pass: process.env.PASSWORD,
    },
});

Real-World Use Case: Sending Verification Emails

When a user signs up for your application, you may need to send a verification email.

Example: Sending a Verification Email

const sendVerificationEmail = (email, verificationLink) => {
    const mailOptions = {
        from: 'your-email@gmail.com',
        to: email,
        subject: 'Verify Your Email',
        html: `
            <h2>Welcome!</h2>
            <p>Please verify your email by clicking the link below:</p>
            <a href="${verificationLink}">Verify Email</a>
        `,
    };

    transporter.sendMail(mailOptions, (err, info) => {
        if (err) {
            console.error('Error sending verification email:', err);
        } else {
            console.log('Verification email sent:', info.response);
        }
    });
};

// Example usage
sendVerificationEmail('user-email@gmail.com', 'https://example.com/verify?token=12345');

Troubleshooting Common Errors

1. Authentication Error:
   Ensure your email and password are correct. If using Gmail, enable “Less secure app access” or set up an app-specific password.
2. Connection Error:
   Check if your SMTP server configuration is correct.
3. Blocked Email:
   Some email providers may flag your email as spam. To avoid this, add SPF, DKIM, and DMARC records to your domain settings.

Common Nodemailer Methods

1. createTransport(): Configures the email transporter.
2. sendMail(): Sends an email with the specified options.
3. verify(): Checks if the transporter is configured correctly.

Example: Verifying the Transporter

transporter.verify((err, success) => {
    if (err) {
        console.error('Transporter setup failed:', err);
    } else {
        console.log('Transporter is ready to send emails.');
    }
});