So very oooooooold:
http://urbanlegends.about.com/library/blwingdings.htm
"Circulating since: Sept. 2001"
"Neither of the airliners involved in the attack on the World Trade Center bore the number "Q33NY." The actual flight numbers were as follows: American Airlines Flight 11 and United Airlines Flight 175. It's clear, then, that someone carefully fabricated the sequence of numbers and letters in the email to achieve the desired effect."
BUSTED! [yes I like that mythbusters show]