You can find postcards all throughout the city, at museums, gift shops, or just little kiosks on the side of the street. I bought postcards on the first day I was there, and at other places throughout my trip. I carried them with me with the intention of mailing them out. But I was too caught up with everything else doing on so, it just didn’t happen. One night, my roommate & I were looking at all the postcards we bought (she bought it as keepsake). I then realized, what do you write on a postcard. I eventually mustered up a few sentences on each post card. I went down to the lobby to ask where is the nearest place I can mail them out. The front desk agent advised me I could go to Monoprix, a grocery store to do this. I head over to Monoprix at 4:45PM, turns out Postal portion closed at 4:30PM. They open at 9AM the next morning, I normally start class at 9AM about 20 mins away. So, I waited until I had a visit and we were leaving at 9:45AM, so I got to go to Monoprix first. As soon as they’re open, I am first in line. Turns out, they only mail within France.
The next day I go to La Poste, to mail 11 postcards to family and friends and paid nearly €15. I mailed my postcards out on July 2nd, and I received them when I returned home on July 21.