In the following example, we will use the built-in mail() function, where, as parameters, client data will be transmitted via a $_POST request.

if ($_POST['submit'])
 {
  $from    = $_POST['from'];
  $to      = $_POST['to'];
  $subject = $_POST['subj'];
  $message = $_POST['msg'];
  $headers = "From: $fromrn";
  $headers .= "MIME-Version: 1.0rn";
  $headers .= "Content-Type: text/plain; charset=windows-1251rn"."Content-Transfer-Encoding: 8bitrn";
  mail($to, "=?windows-1251?B?".base64_encode($subject)."?=", $message, $headers, "-f ".$from);
}
?>