System.Web.Mail, Exchange Server, SMTP Virtual Server

[darin]

I am trying to send email through our Exchange server but
the emails are sitting the queue folder. In the Default
SMTP Virtual Server properties of IIS I *think* I have to
point to our Exchange server somewhere.

Where do I put our Exchange server name?

Here is my code if it's of any value:
using System;
using System.Web.Mail;

public class MailHelper
{
public static void SendMail(string to, string
from, string subject, string body)
{
try
{
SmtpMail.SmtpServer = "localhost";
MailMessage mail = new MailMessage
();
mail.To = to;
mail.From = from;
mail.Subject = subject;
mail.Body = body;
SmtpMail.Send(mail);
}
catch(Exception ex)
{
//exception code
}
}
}

Thanks,
Darin