What is the postal code of Milan Italy?

The general zip code for the city of Naples is 80100. But if you want your letter to arrive safely and quiclky, you really need to add the specific zip for the street. All big cities have lots of zip codes according to the street or city area. For example, the general zip code for Rome is 00100, but then you have 00144 for a certain area or 00166 for another, etc.