[fso301]

5 people living in a vacant lot with no mail receptacle.

The question here is how was the address determined to be a vacant lot? My parents house shows up on Google Earth, Google maps and GPS mapping software as an adjoining vacant parcel.

[SauronOfMordor]

The Post Office has a web facility for validating addresses and getting the Zip+4. As a byproduct, it also lets you know if the street address is not able to receive mail (due to being a vacant lot, or whatever)

[SauronOfMordor]

https://tools.usps.com/go/ZipLookupAction!input.action?mode=1&refresh=true