I'm not in this space in the sense of building some next generation eMail tool but I'm definitely in the market for such tools and I've also been thinking a bit

I'm not in this space in the sense of building some next generation eMail tool but I'm definitely in the market for such tools and I've also been thinking a bit about ways to improve eMail-related processes lately. From my point of view Mailbox for iOS, Mail.app (or the GMail web UI if you don't care about encryption) and SaneBox combined work quite well. Add to that some individual automation using tools like Zapier and additional uncluttering tools such as Unroll.me and you should be good to go. None of those alone is perfect right now but it's good enough for the moment. I'm still looking for a comprehensive solution for dealing with business invoices that reach me via eMail. Unfortunately, tools like Openera or Shoeboxed look quite promising but still fall short of what I need in one way or another.