[hinfaits]

I thought mail was firstly directed to a center dependent only on zip, and it's then further sorted. If the zip is correct, but a parcel ends up on the wrong side of the country, the mistake isn't due to a typo but probably physical mishandling of mail.

[hermitdev]

That was my understanding, too (and the ZIP + 4 were correct). I'm just recalling the excuse they used when my package went to the wrong state and arrived 3 days late.