Show email reminder if receiver didn't respond for certain time
<p>I have one task such that make leave request form using c# in windows application. The steps are as follows.</p>

<ol>
<li>After filling all the fields, mail should send to the manager.</li>
<li>If manager didn't see that email or he didn't give any response for one day, then we have to show a reminder or notification such that "waiting for response" (for example).</li>
</ol>

<p>For the first step I know how to send an email through SMTP. But how to know that manager responds or not for that thread and showing notification (it may be alert message or windows notification). For all these process should I use work flows? 
Any best ways to do it?</p>

<p>Is it better to implement in asp.net or windows application. I am planning to do it windows application.</p>
