After giving the individual the answer, I thought it might be useful to post it here:
The President was in South Florida near enough the date in question to give Mr. Atta an opportunity to scout out the hotel where he was going to stay.
There is absolutely no doubt the terrorists had a Presidential assassination in mind. That's why they didn't target the White House with an airplane. Notice, though, that it's Atta doing this too, as well as the hijackings, and certainly the anthrax attack! This is called "multitasking".
The intended routing for the anthrax letters was from Boca Raton to West Palm Beach mail processing facility to the West Palm airport, to Washington National, and from there through the Brentwood Facility, and then to Capitol Hill. The alternate routing took letter(s) through FDR station in New York.
This would have taken 3 or 4 days (the terrorists thought), and about the time we'd started digging out the rubble at the Pentagon (to be hit with TWO airplanes since it is such a very large building), people around the world would have started falling ill with respiratory anthrax picked up at Washington National and JFK terminals!.
Both Washington DC and New York would be in total panic with refugees fleeing the cities, and further spreading anthrax spores.
The plan didn't work. Instead, ordinary procedures served to sidetrack it. That took all the letters but one to New Jersey.
BTW, the FBI initially hypothesized a "letter" for each and every instance of disease. It didn't take long to disprove that hypothesis. Since the early days of the investigation they've accepted the cross-contamination hypothesis. That's where a contaminated letter went through the mail processing equipment and left behind spores that got affixed to other mail. That mail, in turn, served as a carrier for the spores.
All of that means that the only letters we can claim are those which were found, plus one at Boca Raton. It left a trail! BTW, that letter had been so freshly packaged with anthrax that very little of it leaked out, and then only through the wings (at the corners). The other letters were literally "gushing" anthrax spores right through the paper.
The spores have been found to be small enough to penetrate the paper used by USPS to produce embossed postage paid envelopes.
The spores also readily contaminated whatever trays (MTE) they came into contact with. Some disease incidents are clearly cases of cross contamination where the spores were carried by a letter or flat tray right into the place of business.
Again, that's an ordinary practice you might wish to reconsider. I warned you about keeping those trays around with your stuff in them. Everybody is better off getting them back to USPS as soon as possible where they may end up irradiated, or at least treated with powerful Ultraviolet light which kills any residual spores.
I'm familiar with the attempted assasination in Florida.
Even though I'm intrigued with the mail routing perspective; I'm still not doubting it due to other information I have (not saying I'm right or you are...still pondering).
What about the trip to Maine? Isn't that where Atta attained the anthrax? And his stop off in NJ? I thought that is where he dead dropped some? Remember, the anthrax that went to Washington DC was a different mix. Weren't there two processings? The anthrax that was mailed from NJ and the anthrax that was mailed from FL?
I still think there were two different mixing processes and two different mailings.
And where did you get the information about the letter boxes testing negative? And the packing tape?