System.Net.Mail reads SMTP configuration data out of the standard .NET configuration system (so for ASP.NET applications you’d configure this in your application’s web.config file). Here is an example of how to configure it:
<pre lang="xml"><system.net>
<mailSettings>
<smtp from="test@foo.com">
<network host="smtpserver1" port="25" userName="username" password="secret" defaultCredentials="true" />
</smtp>
</mailSettings>
</system.net>
Hope this Helps out.