This is a Dutch East Indies 1859 Pre Stamp Full Letter, written in Dutch. It was sent to Batavia, with M/S shipping instructions.
This cover has a boxed ZEEBRIEF ONGEFRANKEERED mark in red 76c. It's not particularly strong, but it is there. This is a lovely and well preserved early cover!
Take care because this item, though in very good shape, is still extremely old!