[Telemakhos]

I do have that in my apartment building. But, instead of a code, the lockboxes have keys that only the postman can remove from them. He locks a package in the box, removes the key, and puts it in the recipient's box. When the recipient checks his mail, he uses the key to open the lockbox and withdraw his package. The key is then stuck in the lockbox lock and cannot be withdrawn again except by the postman.

[jollybean]

These were ubiquitous in airports, bus/train stations and shopping malls before 9/11 i.e. 'coin slot storage'.

I guess people born after a certain age won't remember them, but people born before that will see them as obvious.

This exactly the kind of 'robust, localized and low-cost' solution that we have available to us.

[bradlys]

These also exist in sfh developments where mailboxes are grouped together. Usually part of larger planned communities/developments.

[aix1]

That sounds like a pretty cool system.

[pixel_tracing]

Yes common sense sometimes comes across as cool too

[aix1]

Around here the standard protocol is to just leave packages with a neighbour (there's always someone at home) and leave a card telling where the package is.