Having read many of your other comments on these Win10 threads, I suspect that we're going to have to agree to disagree, but here's a weirdly agreeable rebuttal to your reply.
In the email app, when the user activate the command to create a new message, or open the search functionality, the next step is typing, that generally is done with two hands.
Agreed! Fortunately, both of those hands are already going to be at the bottom of the screen, where the New Message button was and where the keyboard will appear. Further, shape writing makes it pretty easy to "type" one-handed on 4"-5" devices.
For the Select functionality the user also needs the other hand to reach the first message of the list in big phones.
The checkbox-select function in WP7/8 was never terribly elegant, mostly because left-right swipes were for changing panels and up/down for scrolling. However, despite this inelegant solution, a
function of the large headers in WP7 and WP8 was that the first item in a list started lower on the screen, making it easier to reach with the hand holding the phone (but not really on a phablet). It's the quest for greater information density that is shrinking headers and driving the top of the list toward the top of the screen and out of the normal reach of a thumb attached to the hand holding the phone.
(Now that I think of it, moving the button bar to the bottom in the coming "small headers" design will make reaching the tops of lists even harder. This is why user interfaces need to be tested to see what user experiences they create. People who beat up MS for "giant headers that do nothing" simply didn't understand that they did something really important -- they preserved reachability despite increasing screen size.
So, the impact of having the buttons at the top is insignificant.
I think that your comments about the keyboard and the top of the list ague for the older design. Welcome aboard! :wink:
People should use the preview before whinning.
That's true for some of what's posted, but it's the very much the wrong verb for a lot of the commentary from A5cent, Spaulagain, me, and others. Here's how you can tell:
Whining: to utter a low, usually nasal, complaining cry or sound, as from uneasiness, discontent, peevishness, etc.
Critiquing: evaluate (a theory or practice) in a detailed and analytical way.
Now, although my tongue was in my cheek for much of that, the point stands that there are valid arguments to be had about what we've seen (and even pencil-drawn mockups). Of course, there are invalid arguments, too. Let's try to avoid the latter ones.