This may be obvious to some, but by calling out to JavaScript within the document hosting your Silverlight application, you can do some powerful things.  Back in the day, we used to sometimes use an href with “mailto” as a poor man’s contact form – hosting solutions with databases and backups weren’t always as cheap and plentiful as they are today.  If you lack a Service Layer to email solution in your environment, you can always try the following:

private void Mailto_Click(object sender, RoutedEventArgs e)
{
    var svc = new Modules.BrowserHostService();
    svc.CallHostFunction("MailTo", "damon@damonpayne.com", "Damon", "Try this Wine!", 
        "Roger Sabon Chateauneuf du Pape 2005", "11F16974-8EE1-4c0c-8AB4-21EF0B7BF087");
}

Where BrowserHostService is part of a demo that I’m working on.  The implementation is very simple:

public class BrowserHostService : IHostService
{
    public void CallHostFunction(string func, params string[] args)
    {
        HtmlPage.Window.CreateInstance(func, args);
    }

This method does everything needed to invoke a JavaScript method on the document containing the Silverlight application.  For invoking the user’s default mail program, you could write a function like what’s shown below.  The only item of note is that the parameter orders must match up.  If you’ve done much Reflection coding you should be used to this.

<script type="text/javascript">
    function MailTo(toEmail, fromUser, subject, suggestTopic, suggestCode) {

        var body = fromUser
        + ' thought you would really enjoy '
        + suggestTopic 
        + ' and there is some info about that on TastingProject.com.   '
        + 'Why not head over to http://localhost:5785/TastingProject.UITestPage.aspx?code='
        + suggestCode 
        + ' and check it out?';

        window.open('mailto:'+ toEmail +'?subject=' + subject+'&body='+body);
    }        
</script>

The preceding C# and JavaScript produces the following result on my machine in Outlook:

Of course you would have to rely on your end user to hit the Send button but this may be a quick and dirty way to get email functionality if you don’t have complete control over your environment.