PHP SENDMAIL

<?php

    if (isset($_POST['email']) && isset($_POST['subject']) && isset($_POST['message'])){
        $emailTo = "YOUR EMAIL";
        $subject = $_POST['subject'];
        $body = $_POST['message'];

        $header = "From: ".$_POST['email'];


        if(mail($emailTo, $subject, $body, $header)){
            $res = array('status' => "ok");
            echo json_encode($res);
        }else{
            $res = array('status' => "bad");
            echo json_encode($res);
        }
    }else{
        $res = array('status' => "bad");
        echo json_encode($res);
    }
?>