- var_dump: documentation ( source)
- filter_var: documentation ( source)
<?php
$email = '"a@b"@php.net';
var_dump(
filter_var($email, FILTER_VALIDATE_EMAIL),
filter_var($email, FILTER_SANITIZE_EMAIL),
filter_var(filter_var($email, FILTER_SANITIZE_EMAIL), FILTER_VALIDATE_EMAIL)
);