SMTP configuration

 Hiii, Can anybudy tell me how to configure smtp settings with web application...
i have tried using asp.net configuration but it's not working... below is my code..
web.config :
<system.net>
        <mailSettings>
            <smtp deliveryMethod="Network"  from="abc@abc.com" >
                <network host="127.0.0.1" port="25" defaultCredentials="true" userName="username" password="password" />
            </smtp>
        </mailSettings>
    </system.net>
and also tell me how to get the port id for our own server.
Thankx in advance ...