If your incoming flight is ontime, then you'll have barely enough time. You'll need to collect your bag from AA then take shuttle #11 all the way around the airport to get back to terminal A. You need to be check your bag by 11:45 am, which should be doable, though not by much. If your inbound is at all late, you won't make it, and I'm guessing this is two different tickets, so DL won't be under any obligation to help you, especially since there's only one daily BOS-YHZ flight.

In short, I wouldn't try it. But good luck if you do!