Exchange Email Sync Issues

[reed4richards]

I'm running the HTC Stock email app with my non-rooted EVO Shift (Android 2.3.3) and just recently started experiencing a problem with Exchange emails. When I get new emails OK, but when I read them on my desktop app, or move/delete them, the emails used to reflect these changes on my phone. Now, they don't.

I haven't updated or changed my phone at all and the email admin at my company said that nothing changed on his end. Does anyone know why this is happening and how to prevent it?

Thanks.