The similarities are not the point.
Look... Someone sends anthrax in the mail. Someone sends a warning letter to the same person at virtually the same time, before anyone else knew that the original letter had been sent. Actually before anyone else knew that any anthrax letters had been sent.
How could anyone else have known who to send the warning letter to?
Why wait a couple of days after the real letter before mailing the warning letter? Be-cause of the incubation period. That's exactly what one would expect.
To all of you contributing to this thread: This has been a VERY interesting and informative exchange,with plenty of new material thrown in,and I appreciate the spirit and cooperativeness of all !
There were much earlier threads about the exact nature of the materials used.Someone-quite a while ago-suggested the materials were made with a very up-to-date technology.
Cabosil (silocaine) was mentioned.This stuff is available "over the counter" for about $ 5.95 pound,and is used in fireworks and (prepared a bit differently) in pharmaceutical products,electronics,and certain paints.
When made "perfectly" in a proper spray dryer (a recent and notable Swiss upgrade of the Russo-Iraqi method),it was actually unsuitable for mailing,because you couldn't get it to hold still long enough to put it into an envelope.
The Russians (and their "clients") used to use a spray dryer to prepare their bioweapons.Instead of using cabosil,they used diatomaceous earth and Bentonite (a water resistant clay)-plus a third,undisclosed material which helped eliminate clumping.It was almost exactly the way we used to make it,before we stopped production in 1972: no surprise,because the Russians had penetrated our program so thoroughly,they were reading copies of our internal reports before the ink was dry on the originals.