The better way to check existence of the domain name.
If domain name exist then email is valid otherwise email is invalid.
<?php
if(domain_exists('test@hotc.nu.in')) {
echo('This email can be accepted as valid.');
}
else {
echo('Domain name doesnot exists; Invalid email.');
}
function domain_exists($email, $record = 'MX'){
list($user, $domain) = explode('@', $email);
return checkdnsrr($domain, $record);
}
?>