Email check is a npm async module for NodeJS, that checks if an email address exists.

It first validates the email through regex, and then pings the relative MX server.

It works with native JS promises (and needs a JS engine that supports them, like Node >= v4.0.0).

npm install email-check

(add "--save" if you want the module to be automatically added to your project's "package.json" dependencies)

emailCheck(email, [opts])

The function signature accepts two arguments and returns a promise, eventually fulfilled with true if the email address exists, or false if it doesn't (please note that if your Internet connection is down, or port 25 is closed – e.g. by a firewall – it will always return false).

• email (string) the email address to check.
• opts (object) the options object.

The options object can have three properties:

• from (string) email address originating the request (defaults to the same value as "email").
• host (string) fqdn of SMTP server originating the request (defaults to the domain name of the "from" email address).
• timeout (number) max allowed idle time in milliseconds (defaults to 5000). If the timeout expires, the promise returns false.

var emailCheck = require('email-check');

// Quick version
emailCheck('[email protected]')
  .then(function (res) {
    // Returns "true" if the email address exists, "false" if it doesn't.
  })
  .catch(function (err) {
    if (err.message === 'refuse') {
      // The MX server is refusing requests from your IP address.
    } else {
      // Decide what to do with other errors.
    }
  });

// With custom options
emailCheck('[email protected]', {
  from: '[email protected]',
  host: 'mail.domain.com',
  timeout: 3000
})
  .then(function (res) {
    console.log(res);
  })
  .catch(function (err) {
    console.error(err);
  });

MIT License