At least in the US, regardless of what the official rules might be (I've never checked) you only need a return address if you want the item to come back to you in the event that delivery fails. If you omit it and drop it in a public box with the correct postage it will reliably show up.
This makes sense because the only realistic way to enforce a non-falsified return address would be to verify government issued ID when accepting the parcel.
It's an interesting point thought that receiving messages does require a physical address. I guess the analogy would be needing to log in to browse the message board but not to post? That would be quite strange.
This makes sense because the only realistic way to enforce a non-falsified return address would be to verify government issued ID when accepting the parcel.
It's an interesting point thought that receiving messages does require a physical address. I guess the analogy would be needing to log in to browse the message board but not to post? That would be quite strange.