Most recent release: https://github.com/LegeBeker/AllDutchZipcodeFinder/releases/tag/0.3.0
This is a program I wrote in my freetime to find all existing dutch zipcodes between 2 numbers containing 4 digits, and generate a file on your desktop with the result. I am not giving a guarantee that all zipcodes are present. I used this create a database of all possible zipcodes: https://github.com/jorritb/dutch-postal-codes