User notification by email. Is there a joint here?

Question

PHP

Here comes the data from ajax

<?php
$model=new models_List;
$id=$_POST['id'];
$user_id = $_POST['user_id'];
$email = Models_UserData::getUserEmail($user_id);

unset($_POST['url']);
unset($_POST['id']);
unset($_POST['user_id']);



if($model->manageOrder($_POST, $id, $user_id)) {
    $response = array("msg" => "Заказ отредактирован, клиент уведомлен по Email", "status" => true);
    $model->orderNotice($email);
}

else
    $response = array("msg" => "Не удалось отредактировать заказ", "status" => false);
    echo json_encode($response);

?>

here is sending a notification to the user

if($model->manageOrder($_POST, $id, $user_id)) {
    $response = array("msg" => "Заказ отредактирован, клиент уведомлен по Email", "status" => true);
    $model->orderNotice($email);
}

if the method
$model->manageOrder
returned true, then this is how
$model->orderNotice($email);
we notify the user by email.
Is it normal to notify the user by email this way (in this part of the code)?

Answer 1

As if it's normal. But it's better to filter POST data from (XSS,SQL) injections.