It went by truck from West Palm Beach, FL to the Philadelphia BMC on September 8 (having been mailed Friday evening, September 7 in Boca Raton.)
That's about one day travel time for an 18 wheeler. So, it was in Philadelphia to be dispatched to a major mailer in the Trenton area on September 10. It could have readily been found and tossed in a tray of other First-Class Mail at the mailer's plant that day, and been on it's way through the nearest MPC (Mail Processing Center) and from there to New York on September 11, or September 12, via ground transportation.
Mail traveling from central New Jersey to New York city does not ordinarily travel by air.
So, yes, all things considered, the lady could have opened that letter on any day from September 13 to September 18, and nothing extraordinary need happen for that to have been possible.
"It went by truck from West Palm Beach, FL to the Philadelphia BMC on September 8 (having been mailed Friday evening, September 7 in Boca Raton.)... So, yes, all things considered, the lady could have opened that letter on any day from September 13 to September 18, and nothing extraordinary need happen for that to have been possible."
Ah, but there's the rub. Something extraordinary *did* happen. The anthrax was mailed *prior* to 9/11.
The FBI spin, however, is that the anthrax attacks were from a domestic enemy who was a 9/11 copycat.
Except, you can't copycat what hasn't happened. And that was my point above...that the FBI "copycat" spin and "domestic enemy" timeline can't be true because the anthrax letter to NBC was mailed **BEFORE** 9/11/2001!