Legit

A wrapper for the NodeJS Dns.resolveMx method that checks the domain of an email address for valid/existence of MX records.

Installation

$ npm install legit

Usage

const legit = require('legit');
 
legit('validemail@validdomain.com')
  .then(result => {
    result.isValid ? console.log('Valid!') : console.log('Invalid!');
    console.log(JSON.stringify(result));
  })
  .catch(err => console.log(err));

If an email addresses domain is legit then the object returned will include an isValid key that will be set to true as well as an mxArray key with all the MX record information for the valid domain.

If the domain has no MX or cannot resolve any MX then it will return isValid as false.

Anything else is considered an error and you'll get it in the .catch

Async/Await Usage

For a more modern approach using ES6, you can await the reponse before acting on it.

const legit = require('legit');
 
(async () => {
  try {
    const response = await legit('validemail@validdomain.com');
    response.isValid ? console.log('valid') : console.log('invalid');
  } catch (e) {
    console.log(e);
  }
})();

Example Response

For a valid email address, you'll get the following response object:

{
  "isValid": true,
  "mxArray": [
    {
      "exchange": "aspmx.l.google.com",
      "priority": 1
    },
    {
      "exchange": "alt1.aspmx.l.google.com",
      "priority": 5
    },
    {
      "exchange": "alt2.aspmx.l.google.com",
      "priority": 5
    },
    {
      "exchange": "alt3.aspmx.l.google.com",
      "priority": 10
    },
    {
      "exchange": "alt4.aspmx.l.google.com",
      "priority": 10
    }
  ]
}

License

(The MIT License)

Copyright (c) 2015-2020 Martyn Davies, and contributors.