why do governments still use secret letters?

I see articles about Iran and America trading letters like this www.reuters.com...

What I want to know is simply what the title states, why do countries still send letters to each other? Seems kind rudimentary. I know they are afraid of emails being hacked but couldn't letters get stolen much easier? And if anybody knows how this process works that would be cool to find out.

i think these letters are personally delivered by personally diplomats thru their respective embassies.

i don't think they use usps.

reply to post by jjf3rd77


And then the letters are opened and read, and an answer given to the messenger to take back to the appropriate person. And thus the game is played.

reply to post by jjf3rd77


Emails can be tracked and hacked and letters can be read
and then burned.