Email Validation Snipet in PHP

Following email validation snipet is useful when implement user registration module on website.

  1: $email = $_POST['email'];

  2: if(preg_match("~([a-zA-Z0-9!#$%&'*+-/=?^_`{|}~])@([a-zA-Z0-9-]).([a-zA-Z0-9]{2,4})~",$email)) {

  3:     echo 'This is a valid email.';

  4: } else{

  5:     echo 'This is an invalid email.';

  6: }