How to verify an email address in Node.js

Verify whether an email address is real and deliverable — in real time, from Node.js, using the MailTester Ninja API. One HTTP call. Nothing is stored on our side.

Code

const url = new URL("https://happy.mailtester.ninja/ninja");
url.searchParams.set("email", "someone@example.com");
url.searchParams.set("key", process.env.MAILTESTER_KEY);

const res = await fetch(url);
const { code, message } = await res.json();
console.log(code, message); // -> "ok" "Accepted"

What you get back

`ok`	Accepted	the mailbox exists and accepts mail
`ko`	Rejected	invalid / undeliverable address
`mb`	Catch-All / uncertain	domain accepts everything, or temporary state

Get a free API key at mailtester.ninja/api. Prefer a quick manual check? Use the free domain analyzer.

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