This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
If I understand correctly you are asking where to download javax.mail from? The package itself can be found java.sun.com - just search for it. Once you download it, put the jars in your classpath, and then you should have access to it.