Notable functionality similar to Google Inbox (RIP) or Shortwave

At this point if I didn't own a grandfathered free gsuite plan I'd move. I already use fastmail for pobox.com which they have kept running seamlessly, their product engineering and standards participation is stellar.

Would recommend. 10/10. Hope they add an Asian/Oz data region option

This was the best feature of Gmail and I missed it once I switched away after they got rid of external POP accounts.

I use Google because inertia wins, but if Fastmail brings back true Google Inbox bundling without breaking IMAP standards, I will migrate tomorrow.