Maybe my standards are low, but the ones categorized as Total failure strike me as kind of okay. Not great humor, but tbh better than half my son's jokes.
I'm not entirely sure the author understood them.
I'm fairly certain the joke here is something like, "you couldn't have known to say you didn't receive the letter unless you actually did get the letter." I'm guessing the translation isn't helping, but it's actually a pretty routine joke. Not a total failure at all!
Sorry I didn't get back to you with those spreadsheet edits, I must not have gotten your email!
Best, -Joe -- Sent from my iPhone