Take the contents of shutdown.xml and place it in
%programfiles%\Windows Small Business Server\Data\Monitoring\ExternalAlerts folder on the SBS 2008 server. (the 64bit subdirectory not the 32 bit one). Then wait a bit of time and you'll see it sent out to you.
The XML file contains the following code:
<?xml version="1.0" encoding="utf-8" ?>
<AlertDefinition ID="896e6561-b29d-42b5-b349-a87460c8556f" Default="1" Title="Unexpected Shut down" Source="Server">
The instructions to build a custom alert are pretty simple. First you need to generate a custom GUID. An easy way to do this is to use http://www.guidgen.com/Index.aspx, to do so. Then place that GUID in that AlertDefinition ID area shown, Default=1 means that it will be default checked, Define the Title of the event, and the Source. Then find the Path and Provider and EventID (the SDK instructions tell you how http://msdn.microsoft.com/en-us/library/cc721719.aspx ) and ensure that you place the </AlertDefinition> and </AlertDefinitions> to close the code.