Mar 02, 2010 11:49 PM|shaikhather|LINK
I had been looking for this too and just found it; solved it by specifying a DeliveryMethod of PickupDirectoryFromIis. For this to work you need to have SMTP Server running.
Dim myMailClient As New System.Net.Mail.SmtpClient(AppSettings("SMTPHost"))
myMailClient.DeliveryMethod = SmtpDeliveryMethod.PickupDirectoryFromIis