Check out Opera 11.60 and get inspiered of the new E-Mail Client

I like the new sorting of the older mails.
They are sorted under the Month for the last year and under the years
for Mails that are from the last year and older.
(Nice slider look)

Here you can see it:

Mails before January are grouped under 2010, 2009, 2008 and Older.