I tried a bunch of different clients during the years. I went through Sparrow before it was bought and killed by Google, I tried AirMail, Polymail, Unibox and Spark. To be honest with you, I wasn’t happy with any of those clients. Don’t get me wrong, they were ok and did the job but I’m a weird person and I like simplicity. Sometimes I want a tool that does one thing and nothing more. Smart inbox is nice, filters are great but I don’t want to use them. I want to get my emails, read them, reply to them and archive them. And that’s it.

Good resource for synching Gmail, Mail.app, and iPhone email.