That's a very nice looking app - I like the look of it it gives me Mail.app vibes.

A mail client is always a tough thing to get right so I'm glad you're working on one

I love then idea that as the total cost (time/money/attention) of personalizing software continues to come down, more people will be able to encourage a diaspora of options, tailored to each niche.

Visually it resembles Mail.app, but if it’s going for a similar level of functionality I think modern GNOME’s hamburger-and-three-dots-buttons approach to menus is going to become a problem.

This is one of those types of app that really benefits from a proper menubar with several top-level menus so the user isn’t stuck spelunking submenu tunnels.