If you walk in Spain through urbanizacíones with walled houses, you regularly encounter nameplates with ‘family’ names such as Buzón and Cartas. Often with ceramic tiles in a classic ornate dark blue and bright yellow design.
And although many Spanish men are called Pedro or Juan or Diego, their second name is not often Buzón or Cartas. Of course, it might very well be the case that someone carries this second name, but buzón actually means mailbox and cartas is Spanish for letters.
^tvo