In the last year, the few QSL responses I have gotten from South
America were not ALL delayed, but the response from Brasilia seemed to
have some trouble getting here and came finally via registered mail.
Yesterday's QSL from Ecuador, likewise, came by registered mail,
although it was not delayed as far as I can tell.

RHCuba keeps threatening (by e-mail) to send a QSL, but they never
come.

Is there some weird postal rule that stuff coming in from Latin
America must be registered or delayed or otherwise? Does such a rule
extend to other nations/continents as well?

Any insights appreciated...thanks!

Bruce