Folded Icon

So, I'm developing this set of icons (32px based) with folded style.
I'm stuck with those mail icon (on the third row) and not really sure which one that inline with the rest of icons.

I like the one with paper folded to the front (first one), but then I'm not really sure it consistent with others.

I also used 3 different fold width for all icons depends on the object (See attachment), with all spacing is not less than 2px.

Any comments and inputs are welcome :)