Formal letter/email outline
1. Naam bedrijf/adres/ postcode + woonplaats/ The Netherlands
of je eigen adres
Bijv.
Scandinavia Travel P. de Leeuw
Herenweg 34 or Keizersgracht 20
8023 DA Zwolle 1234 AB Amsterdam
The Netherlands The Netherlands
All options are correct; the first one is the easiest and the one you should use! Remember to write months with capital letters in English!