I've never lived in a house which didn't regularly receive letters for at least 5+ people who previously lived there. I'm sure your mailman nor any intelligence agencies keep notes on mail arriving with a different name.
Actually, since the NSA disclosures showed that they often photograph postal envelopes, I'm pretty sure that there are databases of names and addresses somewhere...
But you make a good point - if you are going to invent a name, you should probably choose one of the previous occupants.
