$re = '/^[\w\-\.]+@([\w-]+\.)+[\w-]{2,}\:[\S\-\.]+$/m';
$str = 'example@example.com:sdfswe12312
example@gmail.com:sdfswe12312
example@example.co.fr:sdfswe12312
example@example.co.uk:sdfswe12312
john@smith.org::sdfswe12312
0-day@bk.ru:nob0dy
0-fpavs98-ref13@mail.ru:ref123456789
0-frajer@gazeta.pl:forktest1221
0-gun@live.nl:bokto12
0-i@ulmb.com:aq1sw2
0-lens@gmail.com:43867799ABC
0-mentor@bol.com.br:102030wi
0-tomac-0@mail.ru:vjq1994
0.0.0.vadim.0.0.0@gmail.com:ValsV199I
0.0.0.web.host@yahoo.com:kZ1X1Vc1vT
0.00webhostjeff@gmail.com:p95donkey
0.03-3f@sapo.pt:SP@Q_]3w0BE&a-{
0.0@fl-de.com:hggi123
0.0@live.com:sxh3321100
0.0_robert_0.0@live.com:robert1992
0.0asd123@163.com:sls26355';
preg_match_all($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