I recently was on a Christmas Eve flight from DFW to SMF which was delayed (mechanical - one of the engines wouldn't start). I spent quite a bit of time talking to the FAs and learned that they were flying to SMF, then flying the return flight to DFW. The four hour delay meant that they would miss Christmas Eve evening with their families. Due to the delay, the crew would be legal "on paper only" to fly the return flight but technically had exceeded their legal flying time and would have been within their rights to refuse to fly. Supervisors advised the crew to decide for themselves whether to fly the return flight or not. The crew decided to fly. I sent AA an email advising them how much I appreciated the fact that the crew chose to fly so that we, their passengers, could spend the holidays with our families, even though it was at the expense of time with their own families. Today, I receive an email from AA apologizing for the flight delay and advising me that they are depositing 3000 bonus miles in my account. I don't think that AA understood the intent of my letter -- it was NOT a complaint in any way, shape or form, nor was I seeking compensation. It was a thanks to the crew for a professional job. I don't feel right accepting the bonus miles, but the email was a "do not reply" email. Oh well!!