“Perhaps, the “letter is in the mail” and just hasn’t reached us yet. We’ve been sending such “letters”, at least since the invention of radio.”
“Since the invention of radio” is a mere tick of a second, on the grandfather clock of time.
Nor did I intend to convey other wise, just that the letter has been sent. Other possible worlds may have sent their letters much sooner than we did and we may receive it any day now.