Needs UI improvements

I like the simple and minimal touch in the interface but there’s one thing that keeps bothering me is the excessive white empty sidebars that the only thing they do is being a huge button to go backwards- that’s it. It’s too much in my opinion. Not saying they make no sense. They can be handy and comfortable when you need to get back to your inbox quickly. But sometimes when you want a tiny window to look at your inbox on your desktop, the app gets way too huge with those massive sidebars. Maybe an option that they grow smaller (or maybe even disappear) when the window’s width is smaller than a specific amount (maybe 30% of the screens width).

TheARMIM about Newton - Supercharged emailing