You were setting BCC but then overwriting the variable with the FROM
$to = "[email protected]";
$subject .= "".$emailSubject."";
$headers .= "Bcc: ".$emailList."\r\n";
$headers .= "From: [email protected]\r\n" .
"X-Mailer: php";
$headers .= "MIME-Version: 1.0\r\n";
$headers .= "Content-Type: text/html; charset=ISO-8859-1\r\n";
$message = '<html><body>';
$message .= 'THE MESSAGE FROM THE FORM';
if (mail($to, $subject, $message, $headers)) {
$sent = "Your email was sent!";
} else {
$sent = ("Error sending email.");
}