You use email, I use email, everyone uses email! So why don't people pay more attention to how they read and write email?

If you use webmail like Gmail or Hotmail, you probably have ads all over your email! And you might not like computers parsing your personal letters for marketing information. On the other hand, desktop programs like Outlook are expensive and a bit bland.

Mozilla Thunderbird is a free desktop email program that is fast and secure. It includes tons of built-in features like tags, filters and powerful search for a more convenient experience.

It's from the same company that created Firefox, and can be upgraded with add-ons in much the same way. For example, you can try out the popular Lightning calendar add-on. 

Cost: Free

Link: www.mozilla.org

System: Windows XP, Vista, 7, OS X