How does the post office sort mail?

Question

I want to know how the divide it. Do they start with the postal zone it is in or do they start with country then go to state then go to county.....etc.

Answer 1

The machines sort everything out by ZIP Code first...then within streets in that ZIP Code...and finally, the exact building on the street.

Answer 2

By scanning barcodes and some is sorted manually.

The zip code is probably the main thing they look at since an incorrect code can delay a letter about two weeks or more.