Hi,
It is true that we don't have a reference to System.Net from the mojoPortal.Web project since we wrap email methods in a helper class in mojoPortal.Net namespace which is in a different project. So in mojoPortal.Web we only need a reference to mojoPortal.Net.
If you implement your custom code in your own projects as recommended then you can add whatever references you like. I don't recommend you compiling your code into the same projects as mojoPortal.
If using an inline code file just dropped in without adding to the project do this:
<%@ Import Namespace="System.Net" %>
<script runat="server">...
but as Matt has said it is easier to use our helper method.
Note however that our helper method uses the smtp settings from the appSettings section not the ones from the system.net.mailsettings section of web.config.
Hope it helps,
Joe