There is a site that just came out of Beta. SocialMail is an email and discussion board in one. Actually, it's not an email service. It is used in conjunction with your usual email provider.
What is it's function?
This application may make sense for those people that have to communicate with several departments at the same time. You can ask one question and several people will be able to particiapte in the discussion-in real time.
Curious about how it works, I registered my email and sent myself an email at a different email account. It was difficult to navigate. It may be a resourceful tool for people that need answers quickly. I just think that IM would work as well.
Is it user-friendly?
Let's be fair, the site was just launched. This could be why the login was not working properly. It also wouldn't let me check my private messages, even after I received a message alerting me.
I'm going to play around the application for a little while and give it a chance. Perhaps, I'm missing the point.