That's quite a trip!On the Correos labels isn't written the word "Spain" either (I'll post one of these for you to see).I don't remember the longest adventure. I've had some letters delivered after months. For instance.One of the shortest happened yesterday (22 January). A postcard from Austria arrived through the Postcrossing system, and it says that the address was requested on 20 January - ?!
One clue on the SA label is that the cost is in R (for Rand).That is an amazingly quick trip. The only one I've had like that travelled from Paris to the north of England in 2 days.