PHP mail

<?php
$FIRSTNAME = $_POST['FIRSTNAME'];
$COMPANYNAME = $_POST['COMPANYNAME'];
$EMAILID = $_POST['EMAILID'];
$FEEDBACK = $_POST['FEEDBACK'];
$to_address = "[email protected]";
$subject = "Feedback";
$msg = "Sender Name:\t$FIRSTNAME\n";
$msg .= "Company Name:\t$COMPANYNAME\n";
$msg .= "Sender E-Mail:\t$EMAILID\n";
$msg .= "Feedback:\t$FEEDBACK\n\n";
$from = '$EMAIL';
$headers = "MIME-Version: 1.0\n";
$headers .= "Content-type: text/plain; charset=iso-8859-2\n";
$headers .= "From: $from\n" . "Reply-To: $from\n"
 ."X-Mailer: PHP/" . phpversion() . "\n";
mail($to_address, $subject, $msg, $headers, $from);
?>