Good start
Good idea to have native app for Google’s attempts to make email management more feasible. But if you are going to make a native app why not make use of the customization that being native to Mac allows? Currently I cannot put boxy in Full Screen Mode. Also it would be nice to be abale to shift the width of the sidebar by dragging, most mac apps allow this. I cannot read many of my nested gmail folders because the limited left sidebar cuts them off. Please include these features in new releases.
Alpinecalm about
Boxy for "Inbox by Gmail"