It's shocking that this book was actually published. It is rife with grammatical errors, from the first sentence of Chapter 1 to the following howler in Chapter 17:"As e-mail remains the single most used service on the Internet, the killer app or killer apps, many applications will require it, however, with the addition of the JavaMail API, our task as developer easier as we can be free to concentrate on the business logic and can stay away from dealing directly with the various protocols and their associated problems."The mistakes are so pervasive that the book is nearly unreadable. This is unfortunate, because the book actually has a good choice of topics.