Exactly, he simply delivered them to the person who would mail them...which explains the mail date which is after 9/11...wonder if the guys they picked to drop the envelopes even knew what they were mailing?
Not outside the realm of possibility that they are dupes. Time will tell. Whomever is doing it may turn up ill in some emergency room or local health facility.
As of now, I lean toward the theory that it is another cell who undoubtedly has their own supply in storage somewhere and is doing the targeting independently.