$re = '/\w+@\w+\.\w{2,4}\.?\w{0,2}/mi';
$str = 'Os e-mails dos convidados são:
- fulano@cod3r.com.br
- xico@gmail.com
- lucasa_lencarbad@gmail.com
- lauzimirofranca321@hotmail.com
- zezin_br@gmail.com';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php