Código PHP:
$formato = "html";
//*****************************************************************//
$headers = "From: $nombre_origen <$email_origen> \r\n";
$headers .= "Return-Path: <$email_origen> \r\n";
$headers .= "Reply-To: $email_origen \r\n";
$headers .= "Cc: $email_copia \r\n";
$headers .= "Bcc: $email_ocultos \r\n";
$headers .= "X-Sender: $email_origen \r\n";
$headers .= "X-Mailer: [Habla software de noticias v.1.0] \r\n";
$headers .= "X-Priority: 3 \r\n";
$headers .= "MIME-Version: 1.0 \r\n";
$headers .= "Content-Transfer-Encoding: 7bit \r\n";
$headers .= "Disposition-Notification-To: \"$nombre_origen\" <$email_origen> \r\n";
//*****************************************************************//
if($formato == "html")
{ $headers .= "Content-Type: text/html; charset=iso-8859-1 \r\n"; }
else
{ $headers .= "Content-Type: text/plain; charset=iso-8859-1 \r\n"; }
if (@mail($email_destino, $asunto, $mensaje, $headers))
{ echo "Le hemos enviado un correo electronico "; }
else
{ echo "Error "; }