JohnAx, you're absolutely correct that it's bad advice to respond to suspicious emails, and I'm sure everyone appreciates your analysis of unencrypted SMTP. Apologies if my previous post was somehow unclear.

What I was considering in this case was the large quantity of information available in addition to the email, which when taken together suggested strongly that the message was legitimate. Happily, AmericanAirlines has confirmed this conclusion.

Now that you're here, AmericanAirlines, when can we expect the next non-targeted DEQM promotion?