@edmoyse and just to add to this, we're also trying to make this as simple as possible to use. As it's integrated within Gmail, it should be very quick to pick up - nothing more distracting than having to take time out learning a new system.
@JRossTreacher good idea - this isn't going to be available in v1, but might be something we'll add in future. as it's plugged into gmail, any testing would have to use an external service (to avoid your account being labelled as spam)