Spicebird

I was looking for a good alternative to Evolution mail, I found Spicebird from Sourceforge and installed it.   Spicebird has crisp icons and uses a tabbed interface for different utilities such as mail, calendar, contacts, etc., and setting up your existing Gmail address is quick and easy.  The home tab is very useful, it has RSS Feeds, mail folder view, calendar, upcoming events, and date & time.  Date & time is very helpful when you need to view different timezones.