$re = '/^(.+)(\@)(\w+)(\.)(\w{3,4})$/m';
$str = 'some@email.com
yo@email.com
yoo@email.com
212@yahoo.com
@yahoo.com
moreover@.
superb@.com
yahoo.com@superninja.net
hmmer.com@
some@email.body
superb@new.horizon
super.man.followme@neworld.wow';
preg_match_all($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