Recommendation Letter not showing up

<p>So I've gotten two recommendation letters from two teachers and they've already mailed them in. I know that one out of the three privates I've applied to has received the letters because I've already submitted that application (USC). The other two use Common app but they show that no rec letters have been submitted which is strange. The letters were mailed in by post and not through Naviance, which is something my school uses. Does anyone know what might be the reason behind this? And what I should to fix this problem?
Thanks</p>

<p>Items that are delivered by mail are not tracked on the common app site.</p>

<p>oh alright.
Thanks!</p>