Conversation so far:
What was the Judith Miller anthrax hoax about?
On October 12, 2001, Miller opened an anthrax hoax letter mailed to her New York Times office. The act was a copycat hoax of the 2001 anthrax attacks.

Question: Who was the letter mailed from?
Self-contained rewrite: Who was the anthrax hoax letter to Judith Miller mailed from?