Why does Apple Mail close the wrong email first?

Why, when I am composing two emails at the same time, and I close the one I am working on, does apple mail not do that, but closes the one I am NOT working on first??

Is there something I am missing here? because this happens repeatedly and I just wish Applemail wouldn't keep causing me to lose a whole lot of time and information, and have to research and rewrite a whole load of stuff, because it is closing the documents in the background it hasn't been asked to close... smh -

and of course by the time I have found out the wrong one has been dumped, it's too late, because we can't retrieve closed, part-composed emails in apple mail!!.. grrrrr Is there a way of making Applemail close the selected item FIRST, not work in reverse and close the open item waiting in the background?? Thx

[Re-Titled by Moderator]