It is useful if you tag messages, as the tag appears there, also the attachment indicator and the starred indicator.

to each their own, not me, or separate the right and left sides like competitors , still a waste of space either way

Have you considered using the traditional list view. One line, one email. No wasted space there.

appreciate the thought, but I have grown used to the small preview and layout style of outlook and other mainstream mail clients, it would not be so jarring if there was also space at the top but that would get rid of the compact yet functional look i am used to and wish to see return, maybe shunt the icons to the right side