There's also Wmail[1], which I've been using for the past few months. It's essentially just an Electron wrapper around the web app, with all that entails. It's worked fairly well for me, though, and enables easier inbox switching.

[1]: http://thomas101.github.io/wmail/

Huh. Thanks for posting this, I actually hadn't heard of it. It avoids some of my complaints about Boxy[1]; I'll have to give it a try.

[1]: http://www.boxyapp.co/

Great, I hope it works for you!

I've actually done this as well, but it's still not super satisfying. There's still no unified inbox so I have to have two tabs open in the Fluid app, and I don't get notifications or any nice native features like that. On that same grain, Boxy[1] is an unofficial Mac app wrapper for Inbox that adds notification support, but is even worse because it requires me to have a window open for each Gmail account (no tabbed interface).

[1]: http://www.boxyapp.co/

For notifications, there are many Chrome extensions that add that feature to Inbox.

There may be extensions for other browsers as well, but I'm not sure about that.

It would be nice if Google added native support for notifications like they did with GMail though.

It's still very useful sometimes to have an offline copy of your mail, though. I also feel that email is something so integral that it should be a native app.

I've been using Mail.app for years and it's not bad for my needs, but it doesn't have any fancy features, for sure. But the fact that it's native and works decently with mail providers and allows me to manage multiple inboxes quite easily is enough for now.