How to send emails with Nodemailer and AutoSend SMTP

Nodemailer is the most popular email sending library for Node.js. By integrating Nodemailer with AutoSend SMTP, you can send transactional emails from your Node.js applications with reliable delivery, full tracking, and detailed analytics.

Prerequisites

Verified Domain

Make sure you have a verified domain added in AutoSend to send emails from.

SMTP Key

Create a project-specific SMTP key from the SMTP tab in Project Settings.

Configuration

Install Nodemailer

Install the Nodemailer package using your preferred package manager:

npm install nodemailer

yarn add nodemailer

pnpm add nodemailer

bun add nodemailer

Create the SMTP Transporter

Configure the Nodemailer transporter with your AutoSend SMTP credentials:

import nodemailer from 'nodemailer';

const transporter = nodemailer.createTransport({
  host: 'smtp.autosend.com',
  port: 465,
  secure: true,
  auth: {
    user: 'autosend',
    pass: 'AS_xxx', // Your AutoSend SMTP key
  },
});

Field	Value
Host	`smtp.autosend.com`
Port	`465` (recommended) or `587`
Username	`autosend`
Password	Your AutoSend SMTP key (AS_xxx)
Secure	`true` for port 465, `false` for port 587

The SMTP password is no longer your API key. Create a project-specific SMTP key from the SMTP tab in Project Settings.

Send an Email

Use the sendMail method to send your email:

const info = await transporter.sendMail({
  from: '[email protected]',
  to: '[email protected]',
  subject: 'Hello from AutoSend',
  html: '<h1>Welcome!</h1><p>This email was sent via Nodemailer and AutoSend SMTP.</p>',
});

console.log('Message sent:', info.messageId);

The from address must use a domain that is verified in AutoSend. For example, if you verified yourdomain.com, use an address like [email protected].

Verify Delivery

Check the Email Activity dashboard to verify your email was sent successfully. You’ll see delivery status, opens, clicks, and other engagement metrics.

Complete Examples

import nodemailer from 'nodemailer';

const transporter = nodemailer.createTransport({
	host: 'smtp.autosend.com',
	port: 465,
	secure: true,
	auth: {
		user: 'autosend',
		pass: 'AS_xxx',
	},
});

async function sendEmail() {
	const info = await transporter.sendMail({
		from: '[email protected]',
		to: '[email protected]',
		subject: 'Hello from AutoSend',
		html: '<h1>Welcome!</h1><p>This email was sent via Nodemailer and AutoSend SMTP.</p>',
	});

	console.log('Message sent:', info.messageId);
}

sendEmail().catch(console.error);

const nodemailer = require('nodemailer');

const transporter = nodemailer.createTransport({
	host: 'smtp.autosend.com',
	port: 465,
	secure: true,
	auth: {
		user: 'autosend',
		pass: 'AS_xxx',
	},
});

async function sendEmail() {
	const info = await transporter.sendMail({
		from: '[email protected]',
		to: '[email protected]',
		subject: 'Hello from AutoSend',
		html: '<h1>Welcome!</h1><p>This email was sent via Nodemailer and AutoSend SMTP.</p>',
	});

	console.log('Message sent:', info.messageId);
}

sendEmail().catch(console.error);

import nodemailer from 'nodemailer';
import type { Transporter } from 'nodemailer';

const transporter: Transporter = nodemailer.createTransport({
	host: 'smtp.autosend.com',
	port: 465,
	secure: true,
	auth: {
		user: 'autosend',
		pass: 'AS_xxx',
	},
});

async function sendEmail(): Promise<void> {
	const info = await transporter.sendMail({
		from: '[email protected]',
		to: '[email protected]',
		subject: 'Hello from AutoSend',
		html: '<h1>Welcome!</h1><p>This email was sent via Nodemailer and AutoSend SMTP.</p>',
	});

	console.log('Message sent:', info.messageId);
}

sendEmail().catch(console.error);

Advanced Usage

Sending with Attachments

await transporter.sendMail({
	from: '[email protected]',
	to: '[email protected]',
	subject: 'Email with Attachment',
	html: '<p>Please find the attached file.</p>',
	attachments: [
		{
			filename: 'document.pdf',
			path: './files/document.pdf',
		},
		{
			filename: 'image.png',
			content: imageBuffer,
		},
	],
});

Sending to Multiple Recipients

await transporter.sendMail({
	from: '[email protected]',
	to: '[email protected], [email protected]',
	cc: '[email protected]',
	bcc: '[email protected]',
	subject: 'Hello Everyone',
	html: '<p>This email is sent to multiple recipients.</p>',
});

Plain Text and HTML

await transporter.sendMail({
	from: '[email protected]',
	to: '[email protected]',
	subject: 'Hello from AutoSend',
	text: 'This is the plain text version of the email.',
	html: '<h1>Hello!</h1><p>This is the HTML version of the email.</p>',
});

Troubleshooting

Emails not being sent

Verify your SMTP credentials are correct - Check that your sender email domain is verified in AutoSend - Ensure the from address matches a verified domain - Check your application logs for SMTP connection errors

Authentication failed

Double-check your SMTP key is correct - Ensure you’re using autosend as the username - Verify your SMTP key is active in the SMTP Settings - Make sure there are no extra spaces in the credentials

Connection errors

Verify the hostname is smtp.autosend.com - Try using port 587 with secure: false if port 465 fails - Check if your network or firewall blocks outbound SMTP connections - Test connectivity: telnet smtp.autosend.com 465

Emails going to spam

Ensure your domain has proper DNS records (SPF, DKIM, DMARC) - Use a professional sender name and address - Check your domain reputation in AutoSend - Avoid spam trigger words in your email content

Next Steps

Verify Your Domain

Set up SPF, DKIM, and DMARC for better deliverability

Email Activity

Monitor your email delivery and engagement

Webhooks

Set up webhooks to track email events in real-time

SMTP Introduction

Learn more about AutoSend SMTP configuration

Getting Started

Quickstart

Transactional Emails

Marketing Emails

Email Automations

Inbound

Others

Migration

How to send emails with Nodemailer and AutoSend SMTP

Prerequisites

Verified Domain

SMTP Key

Configuration

Install Nodemailer

Create the SMTP Transporter

Send an Email

Verify Delivery

Complete Examples

Advanced Usage

Sending with Attachments

Sending to Multiple Recipients

Plain Text and HTML

Troubleshooting

Next Steps

Verify Your Domain

Email Activity

Webhooks

SMTP Introduction

​Prerequisites

Verified Domain

SMTP Key

​Configuration

Install Nodemailer

Create the SMTP Transporter

Send an Email

Verify Delivery

​Complete Examples

​Advanced Usage

​Sending with Attachments

​Sending to Multiple Recipients

​Plain Text and HTML

​Troubleshooting

​Next Steps

Verify Your Domain

Email Activity

Webhooks

SMTP Introduction

Prerequisites

Configuration

Complete Examples

Advanced Usage

Sending with Attachments

Sending to Multiple Recipients

Plain Text and HTML

Troubleshooting

Next Steps