- var_dump: documentation ( source)
- preg_split: documentation ( source)
<?php
$input = "michael@test.com dave@cheese.com milkman@serverdouche.com";
$email = preg_split("/[-0-9a-zA-Z.+_]+@[-0-9a-zA-Z.+_]+\.[a-zA-Z]+/g", $input);
var_dump($email);