The mail service that you will use in this chapter is SMTP. SMTP, or Simple Mail Transfer Protocol, is an Internet standard for sending email messages that can be received and correctly interpreted by a number of different clients, including POP3 and IMAP.
Perhaps the most important thing to understand about SMTP is that it is used for sending mail, not for receiving it. Thus, in this chapter, when you configure your server to use SMTP mail, you are enabling your Web applications to send messages. But you are not creating a full-fledged email service. There are extensions and other solutions that enable you to make your local workstation able to send and receive messages, but doing so is beyond the scope of this book.
The goal in this lesson is to make it possible to generate messages from within your Web applications and send them over the Interneta useful capability, as you will soon see.