It should come as no surprise that I'm a bit of a fan boy of Microsoft. But I also like being a bit independent in my voice so I offer a moment of critique without any other knowledge of plans than what I see.
Microsoft "Send" is not okay - in fact, it's a terrible, awful, no good, really BAD idea. For more on what it is, see here.
First, I've long since railed that email is NOT a file server - never was, never shall be, never needs to be. Second, and I can't stress this enough - email is NOT an instant messaging platform. One should never treat it as such. Thirdly - AGH!!! okay I'm better :)
MSFT may have grand plans here. I applaud the Garage in all things and they do get a lot of freedom to tweak and play and try new things. That being said, email should be treated as a formal communication medium in the 21st century. Email = Typewriter + Snail Mail from the 20th century. If you need instant messaging, use Skype for Business. If you need file storage, use OneDrive for Business (or their equivalent consumer counterparts).