Create a Gmail account if you do not already have one (http://mail.google.com). Once it is created, play around with it -- send, reply to, receive, and forward some emails. Create some folders and move emails into them. Search for some saved messages. Note that you do all of this using your Web client program, which is executing automatically downloaded Javascript code.
Once you are comfortable with Gmail, download and install the Thunderbird email client (standard install and portable version. You will have to configure Thunderbird, giving it the URLs of two servers -- the one you read your email from -- the POP server -- and the one you use to send email -- the SMTP server. Google has documented the configuration process.
Once Thunderbird is configured and running, play around with it sending, reading, forwarding, replying to, searching for old messages, etc.
Turn in screen shots showing both the browser and Thunderbird accessing your Gmail account.
State and explain the pros and cons of reading your Gmail using a Web client versus an installed client like Thunderbird?
Note that you are getting extra time to do this assignment. If you typically use a dedicated email client like Thunderbird, Outlook or Outlook Express, spend that time using Gmail. If you typically use a browser-based service like Gmail, Hotmail or YahooMail, spend the time using Thunderbird. Using the unfamiliar program for a while will give you experience for comparing it with the one you are used to.