Yahoo! Mail service has been around for ages, and they have definitely made huge changes over the simple mailbox we were all used to 10 years ago. However they have been working harder to make things better for users, however I am still not very comfortable using Yahoo! mail, considering the amount of spam that bypasses their filters.
The spam issue aside, the Yahoo Mail blog announced the launch of a smarter mailbox which has been released to a very small set of users.