<?php 
function is_email($mail)
                {
                  if(
strpos($mail'@') === false) return false;
                  
$host explode("@",$mail); $mxarr = array();
                  
$regexp '/^[-!#$%&\'*+\\.\/0-9=?A-Z^_`{|}~][email protected]([-0-9A-Z]+\.)+([0-9A-Z]){2,4}$/i';
                  if (!
preg_match($regexp$mail)) return false;
                  if (
function_exists('getmxrr') && !getmxrr($host[1],$mxarr)) return false;
                  
                  return 
true;
                }
                if(isset(
$_POST['email']))
                {
                    if(
is_email($_POST['email']))
                    {
                        
$dataReader=$command->query("INSERT INTO email_tbl (email) VALUES (".$_POST['email'].");");

                    }
                }
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