This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
That's the host name or address of the mail server you intend to use. You can use the one you use for your personal mail (in which case you'll need to add authentication code for sending username and password) or run a server on your own machine. Apache James is an example of a server that's pretty easy to get up and running.