[achempion]

I wanted to build something similar that works nicely across different devices (mac/linux) that is fast and supports keyboard-first navigation as I'm also struggling with a similar problem.

When surveying potential users I discovered that most are happy with the web gmail interface and don't really care. It sounds like a very niche requirement and it'll be very challenging to find enough customers (1k+) who would care about using a very nice email client.