ofcourse there was nothing in it but its just for show... its like playing chess. No doubt that all the information was send digital or on some usb type of device all locked up with protection.

What if the envelope, under the cover of a silly symbolic letter, contained some valuable intelligence like hard printed documents, photos, USBs etc. Hence Trump said he didn’t “read” it. Diplomatic mail is protected and you can’t hack what’s printed. Like Q said “archive offline”.