This lightweight module provides precise email address validation, plus optional MX record verification of the domain, returning a Boolean value (true or false).
npm install @sefinek/email-validatoryarn add @sefinek/email-validatorconst emailValidator = require('@sefinek/email-validator');
const TEST_EMAIL = 'contact@sefinek.net';
if (emailValidator(TEST_EMAIL)) {
console.log(`Email ${TEST_EMAIL} is valid.`);
} else {
console.log(`Email ${TEST_EMAIL} is NOT valid!`);
}Beyond syntax validation, you can check whether the domain actually accepts mail by verifying its MX records.
The function lives under the /mx subpath because it depends on node:dns and is therefore not included in the browser bundle.
It accepts a full email address (the domain after the last @ is used) or a bare domain. It never throws and resolves exclusively to a Boolean.
const emailValidator = require('@sefinek/email-validator');
const verifyMx = require('@sefinek/email-validator/mx');
const TEST_EMAIL = 'contact@sefinek.net';
// Cheap, synchronous syntax check first; only hit DNS if it passes.
if (emailValidator(TEST_EMAIL) && await verifyMx(TEST_EMAIL)) {
console.log(`Email ${TEST_EMAIL} is valid and the domain accepts mail.`);
}By default, the system resolvers are used. You can query specific DNS servers (and tune timeout/tries) via the optional second argument. This uses a dedicated resolver and never mutates the global DNS configuration:
await verifyMx('contact@sefinek.net', {
servers: ['1.1.1.1', '8.8.8.8'], // each entry may include a port, e.g. '8.8.8.8:53'
timeout: 2000, // ms per query before a retry (-1 = system default)
tries: 2, // attempts before giving up
validateSyntax: true, // reject syntactically invalid addresses before any DNS lookup
});With validateSyntax: true, the input is first checked against the syntax validator and an invalid address resolves to false without a DNS query. Note that this requires a full email address, so a bare domain is rejected when the flag is enabled.
https://cdn.jsdelivr.net/npm/@sefinek/email-validator@2/dist/email-validator.min.js
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>email-validator</title>
</head>
<body>
<h1>email-validator</h1>
<script src="https://cdn.jsdelivr.net/npm/@sefinek/email-validator@2/dist/email-validator.min.js"></script>
<script>
const email = 'contact@sefinek.net';
if (emailValidator(email)) {
console.log(`✔️ Email ${email} is valid.`);
} else {
console.log(`❎ Email ${email} is NOT valid!`);
}
</script>
</body>
</html>If you find this module helpful, please consider giving the repository a star. For any questions or issues, please create a new Issue.
Copyright © Sefinek. Licensed under the MIT License.
