USPS 'Informed Address' Pilot
usps.com
usps.com
If it's persistent, it's not going to be blind for long.
if its mutable, and multiple of these IDs map to the same physical address, that will be an even bigger adventure for the carriers delivering the mail. Possibly the big regional sorting facilities that do the barcodes will be adding "real" address labels to provide that mapping? Only think I can think of immediately that might work.
I'm more concerned that when an envelope shows up in my mailbox, that I don't know if it's addressed to me or my neighbor. I often end up with the wrong mail in my box, and I just do the nice thing of: a) not opening the mail; b) walking it over to my neighbor's box and placing it there.
With this, I presumably won't necessarily know my neighbor's obfuscated mailbox and would end up having to open the mail in order to determine if I'm the intended recipient. Forwarded mail will also be hard or impossible with this scheme, as well.