I send letters and postcards (poŝtkarto, or bildkarto) sometimes. I thinks you'll see the internet stuff in the related lesson.
- letero = letter
- reto = web
- retletero = e-mail
The course creators are just making you learn words one after each other.
I got a letter just a few days ago. :-)
I found myself thinking of this thread this morning. Isn't email considered a relic from the 20th century these days? We're all about texting and instant messages.