nodemailer
Easy as cake e-mail sending from your Node.js applications
About
Easy as cake e-mail sending from your Node.js applications
Live mirror of the GitHub README. Updated whenever the repo's default branch changes.
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
secureoption. This should be set totrueonly for port 465. For every other port, it should befalse. Setting it tofalsedoes 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
falseto 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
The Nodemailer logo was designed by Sven Kristjansen.
Quick facts
npm install nodemailerHow Sourcemap Explorer detects nodemailer
We catch nodemailer from two complementary signals: bundled source paths and the embedded package.json. Modern bundlers (webpack, Vite, esbuild, Rollup, Turbopack) preserve the original node_modules/nodemailer/ paths inside the JavaScript sourcemap's sources[] array — that's the canonical signal. When the matching package.json is also captured in sourcesContent[], we read the exact version field — patch number included. No regex guessing, no version inference.
- 1
Confirm the site exposes sourcemaps
In DevTools Network, check the response headers of any application script for `SourceMap` or `X-SourceMap`. Failing that, fetch the script's last 4 KB and look for a `//# sourceMappingURL=` comment.
- 2
Find the package in the bundle
Open DevTools → Network → reload. Click any application script and look at its sourcemap. Inside, search `sources[]` for entries matching `node_modules/nodemailer/` — every match confirms the package is bundled. The matching `sourcesContent[i]` for `node_modules/nodemailer/package.json` gives you the exact installed version.
- 3
Read the version directly from package.json
Run `jq -r '. as $m | $m.sources | to_entries[] | select(.value | endswith("node_modules/nodemailer/package.json")) | $m.sourcesContent[.key] | fromjson | .version' bundle.js.map`. Sourcemap Explorer automates the same query in the popup.
Recent versions
FAQ
What is nodemailer used for?
Easy as cake e-mail sending from your Node.js applications
How can I tell if a website is using nodemailer?
Open the page in Chrome with the Sourcemap Explorer extension installed and read the Stack tab. We catch `nodemailer` from two complementary signals: `node_modules/nodemailer/` paths inside the JavaScript sourcemap, and the embedded `package.json` we read for exact-version detection. Without the extension you can do the same lookup manually in DevTools — the steps are listed in the "How Sourcemap Explorer detects" section above.
What is the latest version of nodemailer?
8.0.7, as published on the npm registry. The "Recent versions" table on this page lists the most recent 8 releases with their release dates. Sourcemap Explorer reports the version actually bundled into a site, which can lag the latest release by months on real-world deployments.
Where can I read more?
Project homepage: https://nodemailer.com/. Source code: https://github.com/nodemailer/nodemailer. Published on npm: https://www.npmjs.com/package/nodemailer. Licensed as MIT-0.
Detected by Sourcemap Explorer
When a bundle ships sourcemaps, we read the embedded package.json for nodemailer and report the precise version. Without sourcemaps, an import / require in the page's scripts is enough to flag it.

