Update on the below:
As soon as I turned on my computer and downloaded the emails on my desktop the mail in my pre inbox disappeared.
Originally Posted by bartimole
One suggestion: I turned notification off and my emails seem to be staying right now. I will see if they stay in the box.
My current settings:
Smart Folders: Both switches on
Notification: off
Play sound: on
Show Email: 7 days
Get mail: as items arrive
Mail type: IMAP
Default port, encryption, etc. for incoming and outgoing servers.