text: Want more? Here are some additional resources on this topic:
  Download sample
  This sample shows how to send email over SMTP using classes in the System.Web.Mail namespace..
  Check the SmtpServer property setting. See "Requirements," below, for more information.
  Press F5.
  Internet Information Services (IIS) is required.
  SMTP Service must be installed and running. SMTP Service is an option installed with IIS.
  The SmtpServer property must be set to the IP address or server name where the SMTP Server is running. In most cases this is the "localhost" computer. As such, the SmtpServer property value can either be the friendly name, "localhost", or "127.0.0.1". The latter is the default for this application. To find the SMTP server name:
  Open the IIS snap-in (In Control Panel, open Administrative Tools, and then open Internet Information Services).
  Expand the Default SMTP Virtual Server node.
  Click Domains. In the right pane you will see a list of Domain Names. You may set the SmtpServer property to one of these names or its corresponding IP address.
  The Default SMTP Virtual Server must also be running. Be aware that it is possible for the SMTP Service to be running, but the Default SMTP Server in IIS to be stopped. There is a difference between the service itself and the actual server run by the service. If your Default SMTP Virtual Server is not running, a red X icon will be visible over its node in the IIS snap-in. To start the server, right-click its node and click Start.
  Set the relay restrictions:
  In IIS, right-click Default SMTP Virtual Server and select Properties.
  In the Properties dialog box click the Access tab.
  Click Relay.
  In the Relay Restrictions dialog box, select the box labeled All except the list below. The bottom check box can be selected or cleared.
  This application has a single form with controls similar to the Microsoft Outlook e-mail client. When the form loads, it checks to make sure the user has the SMTP Service installed and that it is running.