Awh man. Operation GunWalker strikes again.
Postal codes in Mexico are issued by SEPOMEX (Servicio Postal Mexicano). They are of five digits and modelled on the US zip code system. The first 2 digits identify a state (or part thereof); and assignments are done alphabetically by state name,
Some one at Glock or at BATF put the 46142 zip code on the shipment, but put USA rather than Mexico on the shipment.
All the police chief has to do is write Mexico on the package and the problem is corrected.