I'm looking for my Sent, Spam,Trash mail. It suddenly disappeared from my screen. What happened to them?

The concern is not "Home Security Devices And Equipment" help related........... Topic moved here to the proper help section for assistance. 

Hi @user_v8azyi, you may have folded down one of these folders. There are usually a few arrows that you may see on the left-hand side panel, have you taken a closer look at the arrows to make sure they are all pointing in the same direction as your other folders?