preg_match_all('/^[a-zA-Z0-9_-.]+@[a-zA-Z0-9-]+.[a-zA-Z0-9-.]+$/', $string, $array);
although it's not very elegant or even false...if it should grep the email adresses out that string...
preg_match_all('/\w[-.\w]*\@[-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]{2,4}/smi' , $string, $result);
would be the more appropriate version
(although not 100% correct =P)
regards