- var_dump: documentation ( source)
- preg_match_all: documentation ( source)
<?php
$subject = '"Joe Smith"<jsmith@example.com>, kjones@aol.com; someoneelse@nowhere.com, mjane@gmail.com';
preg_match_all('^(?:"?([^@"]+)"?\s)?<?([^>]+@[^>]+)>?$', $subject, $result, PREG_SET_ORDER);
var_dump($result);