Try the Windows Live Mail Beta
It seems everyone is following Gmail now. Pretty soon, we will see Gmail Beta, Yahoo Mail Beta, Windows Live Mail Beta all in a dog fight. Although I like the simple interface in Gmail, but I would definitely try out Yahoo! Mail beta if I got an invitation (anyone?). Take a look at a Y! Mail bate review here.
The following is a trick to get the beta for your MSN/Hotmail account:
1. Copy the following link and open it in your browser (Only IE supported!)
2. Sign in your hotmail account
3. Copy/Paste the link again and you should get to a page where you can click on a button labeled “Join Mail Live”
4.Enjoy (All the new features are only supported in IE, but you will see a new interface in Firefox ,though.)