According to what I've been told, all new construction, since about the late 1970's is required to have street mailboxes, and what they call "gang" mailboxes where possible. The complex I lived in a few years back, just squeaked in under the wire of the date and got home delivery, but they told us if we had been completed a couple months later, gang mailboxes would have been required.

Can't speak to the rest of it...that's the limit of my personal knowledge on the issue.