Email Basics
If you use a free online mail program known as a webmail, such as gmail from Google, or a webmail from Yahoo, you won't be opening or storing the mail on your own computer. The mail is stored at a website on the internet.
This saves storage room and protects your computer from viruses that might come in with email.
Below is a video about Google's gmail so you can get an idea of how it works. There are many other webmail sites , including the one offered by yahoo.