<?php
var_dump(filter_var('nonsense.something@dottiness', FILTER_VALIDATE_EMAIL));
var_dump(filter_var('dotty@something.whatever', FILTER_VALIDATE_EMAIL)); // Valid
var_dump(filter_var('foo..bar@gmail.com', FILTER_VALIDATE_EMAIL));
var_dump(filter_var('fooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo@gmail.com', FILTER_VALIDATE_EMAIL));
var_dump(filter_var('"Foo Bar"@gmail.com', FILTER_VALIDATE_EMAIL)); // should be valid
var_dump(filter_var('email@com', FILTER_VALIDATE_EMAIL)); // should be valid
var_dump(filter_var('user@localmachine', FILTER_VALIDATE_EMAIL)); // should be valid
var_dump(filter_var('localuser', FILTER_VALIDATE_EMAIL)); // should be valid
var_dump(filter_var('foo.@bar.com', FILTER_VALIDATE_EMAIL)); // should be INvalid