Sending Emails with SMTP in Node.js

Send emails through AhaSend’s SMTP servers using Node.js with Nodemailer, the most popular and feature-rich email library for Node.js. This guide covers everything from basic setup to advanced features like attachments and custom headers.

Why Nodemailer? Node.js doesn’t have built-in SMTP support, but Nodemailer provides a powerful, well-maintained solution with extensive features including HTML emails, attachments, embedded images, and robust error handling.

Prerequisites

Before you begin, ensure you have:

System Requirements

Node.js installed on your system (Download Node.js)
npm or yarn package manager
Basic knowledge of JavaScript and Node.js

AhaSend Setup

Domain verified in your AhaSend account
SMTP credentials created (username and password)
Access to your AhaSend dashboard for credential management

Need SMTP Credentials? If you haven’t created SMTP credentials yet, check out our SMTP Credentials guide for step-by-step instructions.

Installation

Install Nodemailer in your Node.js project:

npm install nodemailer

yarn add nodemailer

pnpm add nodemailer

For TypeScript projects, also install type definitions:

TypeScript Support

npm install --save-dev @types/nodemailer

Connection Settings

Use these settings for all Nodemailer configurations with AhaSend:

Primary Server

Host: send.ahasend.com
Ports: 587 (recommended), 25, 2525
Security: STARTTLS (requireTLS: true)
Authentication: Required

US Server

Host: send-us.ahasend.com
Ports: 587 (recommended), 25, 2525
Security: STARTTLS (requireTLS: true)
Authentication: Required

Basic Email Examples

const nodemailer = require('nodemailer');

// Create transporter
const transporter = nodemailer.createTransporter({
    host: 'send.ahasend.com',
    port: 587,
    requireTLS: true, // Force TLS
    auth: {
        user: 'YOUR_SMTP_USERNAME',
        pass: 'YOUR_SMTP_PASSWORD'
    }
});

// Email options
const mailOptions = {
    from: '"Your Company" <hello@yourdomain.com>',
    to: 'user@example.com',
    subject: 'Welcome to our platform!',
    text: 'Thanks for signing up. We\'re excited to have you!'
};

// Send email
transporter.sendMail(mailOptions, (error, info) => {
    if (error) {
        return console.log('Error:', error);
    }
    console.log('Email sent successfully!');
    console.log('Message ID:', info.messageId);
});

const nodemailer = require('nodemailer');

const transporter = nodemailer.createTransporter({
    host: 'send.ahasend.com',
    port: 587,
    requireTLS: true,
    auth: {
        user: 'YOUR_SMTP_USERNAME',
        pass: 'YOUR_SMTP_PASSWORD'
    }
});

const mailOptions = {
    from: '"Your Company" <hello@yourdomain.com>',
    to: 'user@example.com',
    subject: 'Welcome to our platform!',
    html: `
        <html>
        <body>
            <h1>Welcome!</h1>
            <p>Thanks for signing up. We're <strong>excited</strong> to have you!</p>
            <p><a href="https://yourdomain.com/get-started">Get Started</a></p>
        </body>
        </html>
    `,
    text: 'Welcome! Thanks for signing up. Visit https://yourdomain.com/get-started to get started.' // Fallback
};

transporter.sendMail(mailOptions, (error, info) => {
    if (error) {
        return console.log('Error:', error);
    }
    console.log('HTML email sent successfully!');
    console.log('Message ID:', info.messageId);
});

const nodemailer = require('nodemailer');

const transporter = nodemailer.createTransporter({
    host: 'send.ahasend.com',
    port: 587,
    requireTLS: true,
    auth: {
        user: 'YOUR_SMTP_USERNAME',
        pass: 'YOUR_SMTP_PASSWORD'
    }
});

const mailOptions = {
    from: '"Your Company" <hello@yourdomain.com>',
    to: 'user@example.com',
    subject: 'Your Invoice is Ready',
    html: `
        <html>
        <body>
            <h1>Invoice Attached</h1>
            <p>Please find your invoice attached to this email.</p>
        </body>
        </html>
    `,
    attachments: [
        {
            filename: 'invoice.pdf',
            path: '/path/to/invoice.pdf'
        },
        {
            filename: 'terms.pdf',
            path: '/path/to/terms.pdf'
        }
    ]
};

transporter.sendMail(mailOptions, (error, info) => {
    if (error) {
        return console.log('Error:', error);
    }
    console.log('Email with attachments sent successfully!');
    console.log('Message ID:', info.messageId);
});

Pro Tip: Use connection pooling for bulk emails, always provide both HTML and text versions, and implement proper error handling with retry logic. Start with sandbox mode during development and use environment variables for credentials.

Testing with Sandbox Mode

Use sandbox mode to safely test your Node.js email integration:

const nodemailer = require('nodemailer');

const transporter = nodemailer.createTransporter({
    host: 'send.ahasend.com',
    port: 587,
    requireTLS: true,
    auth: {
        user: 'YOUR_SMTP_USERNAME',
        pass: 'YOUR_SMTP_PASSWORD'
    }
});

const mailOptions = {
    from: '"Test Sender" <test@yourdomain.com>',
    to: 'test@example.com',
    subject: 'Sandbox Test Email',
    headers: {
        'AhaSend-Sandbox': 'true',
        'AhaSend-Sandbox-Result': 'deliver'
    },
    text: 'This email is sent in sandbox mode for testing.'
};

transporter.sendMail(mailOptions, (error, info) => {
    if (error) {
        return console.log('Error:', error);
    }
    console.log('Sandbox email sent successfully!');
    console.log('Message ID:', info.messageId);
});

const nodemailer = require('nodemailer');

const transporter = nodemailer.createTransporter({
    host: 'send.ahasend.com',
    port: 587,
    requireTLS: true,
    auth: {
        user: 'YOUR_SMTP_USERNAME',
        pass: 'YOUR_SMTP_PASSWORD'
    }
});

const mailOptions = {
    from: '"Test Sender" <test@yourdomain.com>',
    to: 'test@example.com',
    subject: 'Sandbox Bounce Test',
    headers: {
        'AhaSend-Sandbox': 'true',
        'AhaSend-Sandbox-Result': 'bounce'
    },
    html: `
        <html>
        <body>
            <h1>Bounce Test</h1>
            <p>This email simulates a bounce for webhook testing.</p>
        </body>
        </html>
    `
};

transporter.sendMail(mailOptions, (error, info) => {
    if (error) {
        return console.log('Error:', error);
    }
    console.log('Sandbox bounce test sent - check webhooks!');
    console.log('Message ID:', info.messageId);
});

const nodemailer = require('nodemailer');

async function sendSandboxEmail() {
    const transporter = nodemailer.createTransporter({
        host: 'send.ahasend.com',
        port: 587,
        requireTLS: true,
        auth: {
            user: 'YOUR_SMTP_USERNAME',
            pass: 'YOUR_SMTP_PASSWORD'
        }
    });

    const mailOptions = {
        from: '"Test Sender" <test@yourdomain.com>',
        to: 'test@example.com',
        subject: 'Async Sandbox Test',
        headers: {
            'AhaSend-Sandbox': 'true',
            'AhaSend-Sandbox-Result': 'deliver'
        },
        text: 'Testing with async/await pattern.'
    };

    try {
        const info = await transporter.sendMail(mailOptions);
        console.log('Async sandbox email sent successfully!');
        console.log('Message ID:', info.messageId);
        return info;
    } catch (error) {
        console.error('Failed to send sandbox email:', error);
        throw error;
    }
}

sendSandboxEmail();

Sandbox Benefits: Emails sent in sandbox mode are free, trigger webhooks normally, and never actually deliver to recipients - perfect for development and testing.

Environment Variables & Best Practices

Using Environment Variables

const nodemailer = require('nodemailer');
require('dotenv').config(); // npm install dotenv

const transporter = nodemailer.createTransporter({
    host: process.env.SMTP_HOST || 'send.ahasend.com',
    port: parseInt(process.env.SMTP_PORT) || 587,
    requireTLS: true,
    auth: {
        user: process.env.SMTP_USERNAME,
        pass: process.env.SMTP_PASSWORD
    }
});

// Validate required environment variables
if (!process.env.SMTP_USERNAME || !process.env.SMTP_PASSWORD) {
    console.error('Missing required environment variables');
    console.error('Set: SMTP_USERNAME, SMTP_PASSWORD');
    process.exit(1);
}

const mailOptions = {
    from: `"${process.env.FROM_NAME}" <${process.env.FROM_EMAIL}>`,
    to: 'user@example.com',
    subject: 'Environment Test',
    text: 'This email uses environment variables for configuration.'
};

transporter.sendMail(mailOptions, (error, info) => {
    if (error) {
        return console.log('Error:', error);
    }
    console.log('Email sent using environment variables!');
});

# SMTP Configuration
SMTP_HOST=send.ahasend.com
SMTP_PORT=587
SMTP_USERNAME=your_smtp_username
SMTP_PASSWORD=your_smtp_password

# Email Configuration
FROM_NAME=Your Company
FROM_EMAIL=hello@yourdomain.com

Getting Started

Sending with SMTP

Sending with the API

Email Tracking

Integrations

Data Retention

Security

Scaling up

Sending emails in Node.js

Sending Emails with SMTP in Node.js

Prerequisites

Installation

Connection Settings

Primary Server

US Server

Basic Email Examples

Testing with Sandbox Mode

Environment Variables & Best Practices

Using Environment Variables

Resources

Nodemailer Documentation

AhaSend Support

​Sending Emails with SMTP in Node.js

​Prerequisites

​Installation

​Connection Settings

Primary Server

US Server

​Basic Email Examples

​Testing with Sandbox Mode

​Environment Variables & Best Practices

​Using Environment Variables

​Resources

Nodemailer Documentation

AhaSend Support

Sending Emails with SMTP in Node.js

Prerequisites

Installation

Connection Settings

Basic Email Examples

Testing with Sandbox Mode

Environment Variables & Best Practices

Using Environment Variables

Resources