Windows Live Mail to replace Windows Mail
Users of Vista will be familiar with Windows Mail, the built-in email client that has compatibility and stability problems. The primary issues with Windows Mail is that it does not work with a number of free email services, one of them being Gmail, for me that was a big issue as Gmail is my primary email service.
So what are we to do? Well, Microsoft now realizes that Windows Mail is really a piece of junk and is replacing the four month old application with Windows Live Mail Beta 2.0 (herein referred to as WLM).
Full article here: Source