Boy, this one may need a table of contents…
Let’s see, it all started with somebody wondering if you can get a letter back from the postal service once it has been mailed, but before it has been delivered. Maybe you changed your mind about sending the letter, for example. I still don’t know the answer, but I’m guessing if there is no return address on it, forget it. If there is a return address, however, it ought to be possible, right? The sender will get the letter back normally in the case that it is undeliverable, so the sender is essentially a secondary recipient. What does the postal service do with undeliverable mail that has no return address anyway? Shred it? Anyway, this doens’t seem like a satisfactory conclusion in any case, that the return address should play an unrelated role in the mail interception problem.
Which brings me to the second topic. (Read the article)