From SkyNews.com :
US government sources said the anthrax powder sent to Tom Daschle's Capitol Hill office was weapons-grade, and thus almost certainly produced by experts.
Preliminary tests on the powder sent to Daschle indicated it had been refined for easy airborne dispersal. A source said it was a purified form, ideal for use as a chemical weapon.
It makes it likely that the powder was produced in a military laboratory.
I know it sounds funny, but I'm serious as a hog on ice:
DON'T SNIFF YOUR MAIL!