If you watch the demo video, I'm showing a lot more of the functionality - for example the ability that when multiple users send emails via Ivelope, it turns the email into a reddit-like thread with different levels of indentation which is also, I think, the reason why Reddit won over traditional web forums - right now, email is like an old school web forum, but with Ivelope it turns emails into real discussion threads - one of the reasons that Reddit is one of the most popular places to discuss things on.
You also have the separation between emails from people and emails from computers (newsletters/promos) into a separate folder, which is displayed in an overview mode, where you can see the email instantly and also unsubscribe from ANY email with one click of a button :)
Very good point, thank you. So when someone has sent you a task that is not using Ivelope and you click "Mark task as Done", the first time the user will be shown a popup on how to handle this, if he wants Ivelope to send an email every time he sets a task as finished, or if he wants to send an email when all tasks in an email are finished or if he just wants the tasks for his own personal todolist. Having unique features will bring in more users I think.
You also have the separation between emails from people and emails from computers (newsletters/promos) into a separate folder, which is displayed in an overview mode, where you can see the email instantly and also unsubscribe from ANY email with one click of a button :)