Check e-mail address is valid with php

<?php

  // Check e-mail address is valid with php
         $email=$_POST['email'];
          if (!preg_match("/^([a-zA-Z0-9])+@([a-zA-Z0-9_-])+(.[a-zA-Z0-9_-] +)+/",$email))
            {
                  echo "Email Address Is Invalid !";
            }
          else
           {
                 echo "Email Address Is Valid !";
           }
          

?>