<?php
$testText = <<< TEXT
If you are interested in redistribution or republishing of this document in whole or in part, either modified or unmodified, and you have questions, please contact the Copyright@ holders at ยป doc-license@lists.php.net. Note that this address is mapped to a publicly archived mailing list. For security related issues (in PHP or our websites) please contact security@php.net. If you would like to contact the webmasters for some other reason, please write to php-webmaster@lists.php.net. Note that this address is mapped to a mailing list and a newsgroup, so every message you send will be stored in public archives at multiple servers.
TEXT;
preg_match_all("/\b[A-Za-z0-9_\-\.\+]+@[A-Za-z0-9_\-\.]+\b/", $testText, $result);
print_r($result);