Mexican postal system.... it's slow, really slow. One of my brothers lives full time in Mexico (mainland) and it usually takes between 5 - 9 weeks for a letter to arrive (doing some legal stuff for him here and original documents are required). Most of the letters arrive, some don't. I'd say you have a 85% chance of your letters arriving to their destination..... eventually. Mailing a letter from a major resort (reception) works too. If a letter has to be expedited, FedEx is pretty much on the ball. El Boqueron would've been pretty cool to see!