Folks are quite passionate about the software they use to access their email. I fell in that camp for a while but anymore I just don't get it. I think that stems from my intent to touch emails only once, keep my inbox as empty as possible, and use a single archive folder for all emails I want to keep.
My needs in an email app are just as simple. I need an easy way to move an email to either an archive or the trash. That's it. And since there's an internet connection and a Mac with me 99.9% of the times I check email, I do all of it in the browser with Gmail.
That means I have no need for integrations with other apps because I always have a URL to reference an email. I can always grab the link, drop it into a notes field, or save it as part of a reference document. It also means the email is always a click away.
I have no need for fancy folder structures and snoozing mechanisms. They don't make sense to me. It's an extra layer of complexity and decision deferment that delays progress on the requests represented in the emails. I don't want to postpone my action on it for later, I make the decision the first time I see it.
When I read reviews or hear comparisons of new email apps, I'm usually left asking "why?" Why are all these extra features necessary? Why is everyone trying to solve the "email problem?" The extra bells and whistles won't make your decisions for you. It won't write your responses for you. That's up to you.
We all get email. Some of us get a lot more than others. And if you feel you have an email problem, you need to do something about it. The issue isn't the app. Don't complicate matters looking for a third party app. Keep it dead simple and own your decisions. You'll feel a lot better in the end.