$re = '/^(?!1?\d{10}@)[\w-]+(?:\.[\w-]+)*@[\w-]+(?:\.[\w-]+)*\.[A-Za-z]{2,}$/m';
$str = 'howard.testman123@gmail.com
1234567890@gmail.com
18005567890@gmail.com
55555555555@gmail.com
321654575321@anything.org';
preg_match_all($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