Problemi con mail();

[mondobimbi]

<?php
mail("nessuno@example.com", "oggetto", $messaggio,
     "From: webmaster@{$_SERVER['SERVER_NAME']}\r\n" .
     "Reply-To: webmaster@{$_SERVER['SERVER_NAME']}\r\n" .
     "X-Mailer: PHP/" . phpversion());
?>

ciao