regarding sending mail through asp.net web form using IIS SMTP MAIL SERVER

I HAVE WRITTEN THIS CODE  
Dim myMailClient As New System.Net.Mail.SmtpClient
        myMailClient.Host = "127.0.0.1"
        myMailClient.DeliveryMethod = SmtpDeliveryMethod.PickupDirectoryFromIis
        myMailClient.Send("techie_poswal@yahoo.co.in", "manyu_aitpune@yahoo.co.in", "1", "hi")
 
BUT THE MAIL DOES NOT GETS DELIVERED.... IT JUST GETS INTO THE C:\Inetpub\mailroot\Queue...AND STOPS THERE 
...