...than not even E=MC^2 may prove much of a hindrance to "mass teleportation".

Think of it this way: Successful teleportation may not involve
mass - energy conversions at all, instead "successful teleportation"
may use trans-dimensional shifting,
or trans-dimensional passage.

Physically, the visible world around
us is three-dimensional in form...but scientists now theorize there maybe at least six other dimensions.

If you can manipulate those other
dimensions, perhaps like canal-locks,
visible mass may temporarily "disappear" from sight, only to reappear a little later in another
part of the solar system, having taken
a LITTLE "detour" thrOugh those extra dimensions.

It's only theory, and 'science-fiction' speculation, now,
BUT!!!...revolutionary technology
usually starts out as 'science-fiction'
specultion.

cheers.

Jacob