Rules for references when inheriting from base class
<p>Given that Project A is a C# Class Library and that Project B is a console application that has a dependency on Project A.</p>

<p>In Project A the following class is defined:</p>

<pre><code>public class ActionMailNotifier : RazorMailerBase
{
        private readonly string _viewPath;
        private readonly EmailHost _emailConfig;
                   ...
                   ...
}
</code></pre>

<p>"RazorMailBase" is contained in an external dll, ActionMailer.dll, that is referenced by Project A.</p>

<p>In Project B the following class is defined:</p>

<pre><code>public class EmailFareMonitorAlertNotifier : ActionMailNotifier
{
                        ...
                        ...
}
</code></pre>

<p>If ActionMailer.dll is not referenced in Project B the compiler generates an error message indicating that a reference to ActionMailer.dll is required.  Is there a way to structure this such that a reference to the external dll is not required in Project B?</p>
