Very simple setting, but I simply don't get it...

*functions.php*

```
class functions {
    function output_functions() {
        function sendMail($to, $subject, $message){
            //...code...
        }
    }
}

```

*myfile.php*

```
include $_SERVER['DOCUMENT_ROOT'] ."some/subfolders/functions.php";

$myFunction = new functions();
$myFunction->output_functions()->sendMail("mail@mail.com","My Subject","My Message");

```

And I'm getting the Error:

> 
> Call to a member function sendMail() on null
> 
> 
> 

Any help will be highly appreciated!