duDNnsWp

1var dns = require('dns');
2
3function isGoogle(domain, callback) {
4  var parts = /.*@(.*)$/.exec(domain.toLowerCase())
5    , host = parts[1];
6
7  if ('gmail.com' == host || 'googlemail.com' === host) {
8    return callback(null, true);
9  }
10
11  dns.resolve(host, 'MX', function(err, addresses) {
12    var i = addresses.length;
13    
14    if (err) return callback(err);
15    while (i) {
16      if (/(.google.com|.googlemail.com)$/i.test(addresses[--i].exchange)) {
17        return callback(err, true);
18      }
19    }
20    return callback(err, false);
21  });
22}