@canion So much of this can be replicated (or I have already) in Mail.app.
I have a post Brewing about this but... It’s really about love. When you love someone (something) you take the time to build a relationship. No relationship is perfect but you find a way to make it work for you.
This is true of everything.
My friend Garrick asked me, “What’s the common element acrosss all your bad relationships?”
The answer of course is “Me”.
If your relationship with email has never worked with any client you have, then the problem isn’t email or the client, it’s you.
Email services are built for people that don’t love email and never have and never really will.