IIS7 SMTP不起作用。 邮件卡在“Badmail”文件夹中

i'm trying to implement the mail verification on my website. I've read the guides on the microsoft forums, and at the end of the steps they've told me to open 'cmd' and use this syntax

appcmd set config /commit:WEBROOT /section:smtp /from: string /deliveryMethod:network /network.port: int /network.defaultCredentials:True|False /network.host:string /network.userName:string /network.password:string

This got me an error regarding "/deliveryMethod:netword" but i ignored it because i didn't know what to do exactly.

So i tried a method for veryfing the service by creating a txt with

The Source Email
The Destination
Subject
Body of the mail

then i pasted the file in the folder "C:\inetpub\mailroot\ pickup" but after that the mails stuck in the folder "C:\InetPub\MailRoot\ BadMail.

here is the php:

    $to = $fet2['mail'];
$subject = "Verifica Accoutn BoBBa Italia";
$txt = "<html>
<head>
<title>Verifica Account</title>
</head>
<body>
<p>Ciao ".$fet2['username']."</p>
<p>Questa è un messaggio automatico del sistema. Per verificare il tuo account è semplicissimo, ti basta cliccare sul link qui sotto! .</p>
<p>Verifica il tuo account!</p>
<table>
<tr>
<th>Link: clicca <a href='http://beta.bobbaitalia.it/verifico.php?token=".$token."'>QUI</a></th>
</tr>
<tr>
<td>http://beta.bobbaitalia.it/verifico.php?token=".$token."</td>
</tr>
</table>
<p>Grazie per aver scelto BoBBa Hotel Italia.</p>
<p>Non rispondere a questa email, è inattiva! </p>
<p><a href='http://beta.bobbaitalia.it/'>BoBBa Italia</a></p>
</body>
</html>";
$headers = "MIME-Version: 1.0" . "
";
$headers .= "Content-type:text/html;charset=UTF-8" . "
";
$headers .= "From: no reply <no-reply@bobbaitalia.it>";

$email=mail($to,$subject,$txt,$headers);

Thanks in advance to everyone that will help!