- var_dump: documentation ( source)
- preg_match: documentation ( source)
- filter_var: documentation ( source)
<?php
$email = '8w0rohd_434kd3xd@2kya--0hl3hi-rxmux6.rn';
var_dump(array(
'filter_var' => filter_var($email, FILTER_VALIDATE_EMAIL),
'preg_match' => preg_match('/^[a-z0-9!#$%&\'*+\\/=?^_`{|}~-]+(?:\\.[a-z0-9!#$%&\'*+\\/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$/i', $email),
));