Windows XP Home Edition and SMTP server

Hi
I'm developing a model site on my WindowsXP Home edition laptop. So IIS is not installed on my m/c. I'm using VWD Express 2008. I need the web application to send email when a new user is registered. I configured the we.config as
  <system.net>
        <mailSettings>
            <smtp from="someone@gmail.com">
                <network host="localhost" password="somepwd" userName="someone" />
            </smtp>
        </mailSettings>
    </system.net>
On execution, the application displays the following error message:
No connection could be made because the ...