Craig Francis

PHP Email Check

A function to check if an email address is valid, which also includes a DNS look-up to check that the domain name is valid.

function isemail($email) {
if (preg_match('/^\w[-.\w]*@(\w[-._\w]*\.[a-zA-Z]{2,})$/', $email, $matches)) {
if (function_exists('checkdnsrr')) {
if (checkdnsrr($matches[1] . '.', 'MX')) return true; // If a 'mail exchange' record exists
if (checkdnsrr($matches[1] . '.', 'A')) return true; // Mail servers can fall back on 'A' records
} else {
return true; // For Windows
return false;

Please note that in some environments, like on the Windows OS, you might find that the DNS look-up is ignored, or might take a few seconds to time-out... so please test thoroughly.

Any feedback would be greatly appreciated. If you would like to use this code, please read the licence it is released under.