Can you drop off returns during closed hours? Like at post office. Or do they lock the door when closed?

Dropoffs can only be done during business hours.

You can only dropoff during the times they are open.

No. You can only drop off when they're open.

You cannot drop off when they are closed

Nope, unfortunately Amazon@Columbus only accepts returns during their business hours. It'd definitely be helpful if there was a "drop box"

Unfortunately, no.