Can you tell me what SSL is?
SSL stands for
Secure Sockets Layer. Internet networking is conceptually organised into a number of different stacked layers of abstraction that use each other's services. At the bottom of the stack is the
physical layer which sends data over the physical medium, such as the radio of your WiFi or the twisted pair cable of your Ethernet. At the top is the
application layer, an example of which is
http (the
HyperText Transfer Protocol) used by the World Wide Web. Http is concerned with locating and transferring hypertext resources (web pages, broadly speaking) around the network. In the address bar on your browser you can see examples of web addresses or
URLs (
Universal Resource Locators) used by http to reference the webpage you are currently on.
The application layer uses a lower level layer called the
session layer to initiate and mediate a conversation with a particular server on the network. The session layer is where SSL resides. It manages encrypted sessions with servers, including the initial exchange of encryption keys. When http sits on top of SSL it is referred to as https. In your browser you will see either that URLs start with https:// (instead of
http://), or your browser will display a padlock symbol next to the address bar. Each website determines whether you can, or
must, use https when communicating with it -- you don't generally get to choose this yourself.
Once you are using https to a website you can be reasonably certain your communication with that site is secure. However, not all applications on the internet are web servers and browsers. Your email uses a different application layer protocol to communicate with an email server. A common one is SMTP, the
Simple Mail Transfer Protocol. Once again you have the option of running on top of SSL if your mail server supports it. There will be a setting somewhere in your email client, though it might also be referred to as TLS, for
Transport Layer Security.
Note that this only applies if you are running an email client program. Lots of people use web mail, which is an ordinary web site accessed via the browser. In that case just make sure that your provider uses https on the site.