What e-mail application do I need?
Well, you may not need an application at all. Many mail services (GMail,...
Well, you may not need an application at all. Many mail services (GMail, Yahoo, and such) have web interfaces that take care of that for you. If you have to connect to something like an exchange server, you likely already have the application you need, since most distributions include one.
In your list of applications/programs, look in categories called "Internet" or "Office". If you see something like Thunderbird, Evolution, Claws, or KMail, you've got what you need. If not, go to the Software Center (or however you are getting your software) and just search for one of these programs.
Hope this helps!