This doesn't really mean anything. Is a RAM chip a medium? How about a traveling EM wave? What about punchcards?
But regardless of that question, a copy is made when a copy is made. "This tape will self-destruct in 30seconds" does not mean that it is somehow magically not a copy.
Actually, there are probably several copies made during the course of the network transfer of a file, from the original disk to network buffers, from router to router, back into memory and then onto disk. Most of those copies are transient. It's possible they're not sufficiently "fixed" that the law might consider them ephemeral.
The point is that a copy is made, by you, at the endpoint. When you save a song to disk, a copy is made. The number of copies that were made to get it to you is totally irrelevant to that fact.
This just doesn't work. Simple logic tells us that if the copy is being made here, then the posession of the original must be transferred here, leaving the sender without a copy. This isn't happening. When I send you a file, I'm sending you a COPY, not the original.
What you're sending isn't a copy, but you're correct it's not the original.
You are ignoring the statutory definition of a copy, and substituting it with your own. That's fine, for the purposes of philosophy, but we are discussing what is and isn't legal.
You cannot send someone a copy, by definition, unless you are sending them a physical thing: like a CD or a disk or a book or a painting. If you read someone a book over the phone, you're not "sending them a copy," you're performing the work.
A copy is a tangible, actual object. It is not a stream of bits flowing over a network. Or words flowing across the air. It is not an electromagnetic wave. The statute is exceedingly clear on what constitutes a "copy."
The copy is made when it is made material, when it is fixed in a medium sufficiently that it can be perceived, on its own, or with the aid of a machine. The copy is made where you write down the story I tell you. Or where you record the sounds you hear. Or where you save to disk the bits that you receive.
You could argue that "archival" is being done on the US side, but the copying is definately being done on the other side of the ocean.
There's no such thing as "archival" at copyright law. The thing you call "archival" is what the law calls "copying." Take it for what you will.