As a bit of constructive criticism, I suggest that you not mark orders "Shipped" when they have not yet been picked up by USPS. It confuses your customers, as "Shipped" boxes can be stuck in your 'shipping queue' for upwards of a week with the tracking number showing that the USPS does not have them. If it's in your "shipping queue" it should still say "processing"

I know you are swamped with orders lately, but why is there a "shipping queue" of ready-to-ship boxes that can't be dropped off at the Post Office? Does the Post Office only accept a certain number of packages per day?