Creating an Address Book You can't even remember your mother-in-law's name, so how do you expect to remember her e-mail address? Thunderbird's address book helps you do what computers were made to do - remember mundane details for us. After you build up your address book, Thunderbird helps you compose e-mails to your friends, family and coworkers easily. Creating an address book can be a chore, but Thunderbird simplifies the task by helping you build it automatically. Whenever you send an e-mail, Thunderbird automatically adds the e-mail's recipients to your address book. Even though you don't necessarily want everyone you e-mail in your address book, having them there doesn't really hurt anything because searching for an address later takes about the same amount of time even with a handful of unnecessary addresses. If you want to manually add an address to your address book, you have two ways to do it. If the person you want to add sends you an e-mail, you can add his or her address from the e-mail itself. The Message pane already contains the sender's address, so just click it (with either the left or right mouse button) and choose Add to Address Book from the menu that appears, as shown in Figure 10-9. Figure 10-9: Build your address book quickly and easily from the Message pane. Otherwise, if you know the person's e-mail address, you can manually create a new card (which is like a record) in your address book by choosing File New Address Book Card and filling out the window that appears. You can enter all sorts of information into an Address Book card, but filling out the first name, last name, and e-mail address is a good place to start. After you add a name and address to your address book, Thunderbird can suggest it when you begin typing either one into the address field of an e-mail, as I discuss in the earlier section, "Composing E-Mails." You can also select it manually from the Contacts Sidebar of the Compose window, which I also discuss in that section.           Blocking Junk Mail Every time I receive an e-mail from a friend in Peru, I stop to marvel at the amazing technological advances. But then the Viagra spam arrives, depriving the moment of its magic. Unsolicited e-mails - known bitterly as spam, or junk mail in Thunderbird - are a frustrating reality of the online experience. But Thunderbird takes broad and innovative strides to making them a thing of the past. The system is simple and works like this: Thunderbird begins life stupid. It can't really tell the difference between a legitimate e-mail and junk e-mail, so you have to manually indicate the junk e-mail. However, as you identify junk e-mails, Thunderbird learns what junk looks like and begins to recognize it on its own. When you're confident in Thunderbird's ability to recognize junk e-mail, you can tell it to automatically move junk e-mail to a special Junk folder that