Would a foreign government hand over a vial
of highly dangerous aerosoled anthrax
to a bunch of schmucks
who have no experience in handling such stuff,
or would they insist on filling the envelopes themselves
in their highly secure labs,
and then passing them back to the terrorists,
(maybe in Prague),
for them to carry back to the USA?
In which case, Atta, or somone,
handed over the original handwritten letters,
which were carried back to (?) to be photocopied
and inserted in the anthrax laced envelopes
also previously addressed.
To me, the answer is obvious.