Get $email from row depending on the id

I want every time I click the delete button, this row is deleted and an email is automatically sent to the user that it has been deleted.

I have a table with users and in every row there is a “DELETE” btn. When click “DELETE” btn run delete.php.

The code in delete.php Delete successfully the row but the problem is that I dont no how can get user’s email for the clicked row.

$email=?

(Τhe only thing that interests me at the moment is the solution of the problem and not the security problems that exist)

delete.php

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "userform";

// Create connection
$con = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($con->connect_error) {
  die("Connection failed: " . $con->connect_error);
}

$sql = "SELECT name, email, code, status, lname, checkin, checkout, mnumber, totalprice, rescode FROM usertable";
$result = $con->query($sql);

$email = "SELECT email FROM usertable WHERE id='" . $_GET['id'] . "'";

$sql = "DELETE FROM usertable WHERE id='" . $_GET['id'] . "'";


if ($con->query($sql) === TRUE) {
    echo "Deleted successfully";
    // SEND CANCELLATION EMAIL
    $subject = "DELETED";
    $message = "DELETED REQUEST";
    $sender = "From: myemail@gmail.com";
    $email = ?;
    mail($email, $subject, $message, $sender);

  } else {
    echo "Error cancelled record: " . $con->error;
  }

$con->close();
?>```