ciao...ho un problema, non riesco ad inviare le mail in automatico da php.
praticamente sto facendo un forum e nel caso in cui l'utente perda la password gli viene spedita una nuova password (di default) per mail.
Il codice è questo, non mi da errori e viene visualizzata il messaggio che la mail è stata spedita, ma in realtà non arriva nessuna mail, come posso fare?

if ($lostinfo == "password"){
//if the user has lost his password he should insert his username and the system will send him a new default pwd
?>
<h1>Password lost</h1>

<form name="adduser" method="post" action="lostpassword.php">


Insert your username

<input type="text" name="username" /></p>


<input type="submit" name="Submit" value="Submit" align="center" /></p>
</form>
<?
//define the receiver of the mail
$user= $_POST['username'];
$sql= "SELECT * FROM user WHERE username='".$user."'";
$result = mysql_query($sql, $connection)
or die("Couldn't perform query $sql </br>".mysql_error());
$row = mysql_fetch_array($result);
if($row == null){
echo "error";
}
$to = $row['email'];
//define the subject of the email
$subject = 'Password';
//define the message to be sent. Each line should be separated with \n
$message = "This mail is automatically generated.\nThe new password for the SOUND OFF Forum is password, you should change this password once logged in into the system\r\n";
//define the headers we want passed. Note that they are separated with \r\n
$headers = "From: admin-sound off-forum\r\nDo not reply to this email";
//send the email
//$mail_sent = mail( $to, $subject, $message, $headers );
$mail_sent = mail( $to, $subject, $message );
//if the message is sent successfully print "Mail sent". Otherwise print "Mail failed"
//echo $mail_sent ? "Mail sent" : "Mail failed";

//set the default password as the password of the user
$cryptedpwd=md5('password');
$sql="UPDATE user SET password='".$cryptedpwd."' WHERE username= '".$user."'";
$result = mysql_query($sql, $connection)
or die("Couldn't perform query $sql </br>".mysql_error());

if ($mail_sent) {
echo "

Message successfully sent to".$row['email']."</p>";
} else {
echo "

Message delivery failed...</p>";
}


grazie 1000!!!