nodemailer

What is nodemailer?

Nodemailer is a module for Node.js applications to allow easy email sending. It supports various transport methods and has a simple setup process for sending emails.

What are nodemailer's main functionalities?

Send Emails

This feature allows you to send emails using Nodemailer. The code sample shows how to set up a transporter using Gmail, define mail options, and send an email.

const nodemailer = require('nodemailer');

let transporter = nodemailer.createTransport({
  service: 'gmail',
  auth: {
    user: '[e-mail]',
    pass: 'yourpassword'
  }
});

let mailOptions = {
  from: '[e-mail]',
  to: '[e-mail]',
  subject: 'Test Email Subject',
  text: 'Hello world?',
  html: '<b>Hello world?</b>'
};

transporter.sendMail(mailOptions, function(error, info){
  if (error) {
    console.log(error);
  } else {
    console.log('Email sent: ' + info.response);
  }
});

HTML Email Content

Nodemailer allows you to send HTML content in your emails. The code sample demonstrates how to send an email with HTML content.

const nodemailer = require('nodemailer');

let transporter = nodemailer.createTransport({
  // transport configuration
});

let mailOptions = {
  from: '[e-mail]',
  to: '[e-mail]',
  subject: 'HTML Email',
  html: '<h1>Welcome</h1><p>That was easy!</p>'
};

transporter.sendMail(mailOptions, function(error, info){
  // callback
});

Attachments

Nodemailer supports sending attachments in emails. The code sample shows how to attach a file to an email.

const nodemailer = require('nodemailer');

let transporter = nodemailer.createTransport({
  // transport configuration
});

let mailOptions = {
  from: '[e-mail]',
  to: '[e-mail]',
  subject: 'Attachment',
  text: 'Please find the attachment.',
  attachments: [
    {
      filename: 'file.txt',
      path: '/path/to/file.txt'
    }
  ]
};

transporter.sendMail(mailOptions, function(error, info){
  // callback
});

Custom Transport Methods

Nodemailer allows the use of custom transport methods for sending emails. The code sample illustrates how to use a custom transport plugin.

const nodemailer = require('nodemailer');
const customTransport = require('my-custom-transport');

let transporter = nodemailer.createTransport(customTransport({
  // custom transport options
}));

// send mail with defined transport object
transporter.sendMail({
  // mail options
}, function(error, info){
  // callback
});

Other packages similar to nodemailer

mailgun-js

A simple Node.js module for Mailgun. Mailgun-js is designed to work with the Mailgun API for sending, receiving, and tracking emails. It's similar to Nodemailer in functionality but is specifically tailored for Mailgun's service.

postmark

The official Node.js client library for interacting with the Postmark API. This package is intended for sending emails through Postmark's transactional email service. Unlike Nodemailer, which is more generic, Postmark is focused on providing a robust service for transactional emails.

aws-sdk

Amazon Web Services SDK for JavaScript in Node.js. It includes support for SES (Simple Email Service), which can be used to send emails. While Nodemailer is a standalone package for email, aws-sdk is a comprehensive cloud services SDK that includes email sending capabilities among many other AWS services.

README

Nodemailer

Send emails from Node.js – easy as cake! 🍰✉️

See nodemailer.com for documentation and terms.

[!TIP] Check out EmailEngine – a self-hosted email gateway that allows making REST requests against IMAP and SMTP servers. EmailEngine also sends webhooks whenever something changes on the registered accounts.

Using the email accounts registered with EmailEngine, you can receive and send emails. EmailEngine supports OAuth2, delayed sends, opens and clicks tracking, bounce detection, etc. All on top of regular email accounts without an external MTA service.

Having an issue?

First review the docs

Documentation for Nodemailer can be found at nodemailer.com.

Nodemailer throws a SyntaxError for "..."

You are using an older Node.js version than v6.0. Upgrade Node.js to get support for the spread operator. Nodemailer supports all Node.js versions starting from Node.js@v6.0.0.

I'm having issues with Gmail

Gmail either works well, or it does not work at all. It is probably easier to switch to an alternative service instead of fixing issues with Gmail. If Gmail does not work for you, then don't use it. Read more about it here.

I get ETIMEDOUT errors

Check your firewall settings. Timeout usually occurs when you try to open a connection to a firewalled port either on the server or on your machine. Some ISPs also block email ports to prevent spamming.

Nodemailer works on one machine but not in another

It's either a firewall issue, or your SMTP server blocks authentication attempts from some servers.

I get TLS errors

• If you are running the code on your machine, check your antivirus settings. Antiviruses often mess around with email ports usage. Node.js might not recognize the MITM cert your antivirus is using.
• Latest Node versions allow only TLS versions 1.2 and higher. Some servers might still use TLS 1.1 or lower. Check Node.js docs on how to get correct TLS support for your app. You can change this with tls.minVersion option
• You might have the wrong value for the secure option. This should be set to true only for port 465. For every other port, it should be false. Setting it to false does not mean that Nodemailer would not use TLS. Nodemailer would still try to upgrade the connection to use TLS if the server supports it.
• Older Node versions do not fully support the certificate chain of the newest Let's Encrypt certificates. Either set tls.rejectUnauthorized to false to skip chain verification or upgrade your Node version

let configOptions = {
    host: "smtp.example.com",
    port: 587,
    tls: {
        rejectUnauthorized: true,
        minVersion: "TLSv1.2"
    }
}

I have issues with DNS / hosts file

Node.js uses c-ares to resolve domain names, not the DNS library provided by the system, so if you have some custom DNS routing set up, it might be ignored. Nodemailer runs dns.resolve4() and dns.resolve6() to resolve hostname into an IP address. If both calls fail, then Nodemailer will fall back to dns.lookup(). If this does not work for you, you can hard code the IP address into the configuration like shown below. In that case, Nodemailer would not perform any DNS lookups.

let configOptions = {
    host: "1.2.3.4",
    port: 465,
    secure: true,
    tls: {
        // must provide server name, otherwise TLS certificate check will fail
        servername: "example.com"
    }
}

I have an issue with TypeScript types

Nodemailer has official support for Node.js only. For anything related to TypeScript, you need to directly contact the authors of the type definitions.

I have a different problem

If you are having issues with Nodemailer, then the best way to find help would be Stack Overflow or revisit the docs.

License

Nodemailer is licensed under the MIT No Attribution license

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The Nodemailer logo was designed by Sven Kristjansen.