<?php 
    $to = "laundrybuoy@gmail.com"; // this is your Email address
    $from = $_POST['email']; // this is the sender's Email address
    $first_name = $_POST['name'];
    $subject = "Form submission - ".$_POST['subject'];
    $subject2 = "Copy of your form submission - ".$_POST['subject'];
    $message = $first_name . " wrote the following:" . "\n\n" . $_POST['message'];
    $message2 = "Here is a copy of your message " . $first_name . "\n\n" . $_POST['message']. "\n\n" ."We will get back to you soon.";

    $headers = "From:" . $from;
    $headers2 = "From:" . "admin@laundrybuoy.com";
    mail($to,$subject,$message,$headers);
    mail($from,$subject2,$message2,$headers2); // sends a copy of the message to the sender
    header('Location: index.html');
    // You can also use header('Location: thank_you.php'); to redirect to another page.
    // You cannot use header and echo together. It's one or the other.
?>