Did you know that you can send mail from the Vatican? It does not go through Poste italiane. Poste Vaticane has it’s own stamps and postmarks. As far as I can tell, there is only one Vatican City Post Office. It is on the south side of St. Peter’s Square, just as you exit the Basilica. When I was there in April 2013, there was also what appeared to be an “annex” in the shape of a motor home, a little east of the actual post office, also in the square. I do not know if you can actually purchase stamps at the “annex”.