In Germany they're needed as well. And in my home town there's actually two streets with the same name in very different parts of the city, distinguishable by p

In Germany they're needed as well. And in my home town there's actually two streets with the same name in very different parts of the city, distinguishable by postcode. Furthermore, they ease automatic sorting and sure, once your mail reaches your local postperson, they know the neighborhood and names and addresses, but that doesn't mean postcodes don't serve a purpose.