Regular matching mailbox

// Mailbox validation :
/**  The verification logic that the goal satisfies : @ There must be content before and only letters （ Case write ）、 Numbers 、 Underline (_)、 minus sign （-）、 spot （.） @ And the last . There must be content between and only letters （ Case write ）、 Numbers 、 spot （.）、 minus sign （-）, And the two points cannot be next to each other  @ the last one . There must be content and the content can only be letters （ Case write ）、 Number and length is greater than or equal to 2 Bytes , Less than or equal to 6 Bytes `  The verification logic is not satisfied : [email protected]…com [email protected],com [email protected] [email protected]?q?.com [email protected]@qq.com [email protected]@139.com [email protected] [email protected])m [email protected]?￡QQ.COM [email protected]___.com.cn [email protected]_163sadasdf.com.cn  Logical : [email protected] [email protected] [email protected] */
$pattern = '/^[\w-.][email protected][a-z\d-]+(\.[a-z\d-]+)*\.[a-z\d]{2,6}$/i';
$res = preg_match($pattern, $subject);
echo $res ? ' yes ' : ' Not ';
echo '<hr>';