Package has arrived. I asked the guy if he would have been able to leave it. It may depend on the particular carrier. Royal Mail can usually leave Amazon parcels. But this carrier does not allow valuable packages to be left. At least, that's what he said.
He showed me the Amazon label. I'd never noticed this before, but every Amazon package actually has your phone number on it. It's in tiny print, the penultimate element in the long barcode on the packet. If you are not in, he's supposed to phone that number.
He'd got a van full of stuff, all still to be delivered (hopefully before 7pm).