$re = '/^\w+(\.[\w-]+)*@([\w-]+\.)*\w([\w-]+\.)+[\w-]+$/m';
$str = 'lqw0@xs4dys3.ugch
aybg6_o2u@5h3ldf2.owu
1qq@o9ktoel7r5i.bhe
bvp3wvq@p1idtm.yk
ppc@ebur3k8dz7x5oto.lxux
8nvy76@xd2mxvenu4n.hl
0im5l20bpre7lqce6@s8pz941v.au
rc@bmn4n.da
i6altyo3@zcvv3383f.tvhg
njvg@71ya.scof';
preg_match_all($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