Missive is a central hub for all your team communications, both internal (chat) and external (emails, Twitter, Fb, SMS). We offer an email client like interface (thread based).

The key difference is we offer internal chat (no tied to external conversations) and the UI is more akin to your email client. You consume everything from an Inbox.

Missive really feels like a snappy email client, a lot of our paying users even use it alone (not in a team context) just because they like the UI. (https://www.youtube.com/watch?v=j95F4sr5Qdw)