Ciao,
cambialo in questo modo e fammi sapere:
Codice:
<?php
$to = 'myAddress@myDomain.com';
$subject = 'the subject';
$message = 'hello';
$headers = 'From: theWebmaster <una_email_esistente_del_tuo_dominio@dominio.est>' . "\r\n";
$headers .= 'Reply-To: <webmaster@dominio.est>';
//aggiungerei anche
$headers .= 'Return-path: <webmaster@dominio.est>';
mail($to, $subject, $message, $headers);
?>