item to open and examine each blocked window individually. Figure 9-3: Firefox displays a menu item beginning with the word Show for each blocked popup window. When you choose a Show menu item, the popup window appears on your screen. Allowing certain Web sites to open popup Windows If you frequent a Web site that uses a popup window legitimately - such as a bank that integrates one into its login process - you might find it inconvenient to have to open it manually each time by using the steps in the preceding section. Instead, you can permanently allow that particular site's popup windows to appear. Popup windows from other sites continue to be blocked. Follow these steps to allow a Web site to open popup windows: 1. Visit the Web site that tries to open the popup window you want to view. 2. When Firefox blocks the popup, click the Options button at the right end of the notification bar. 3. Choose the first option, which begins with the phrase "Allow popups for" and contains the Web address of the site you're viewing. Firefox doesn't show the popup it has already blocked. However, Firefox won't block any popup windows that the Web site tries to open in the future. To view the blocked window, follow the directions in the preceding section, "Opening blocked popup windows." What do you do if you allow a site to show popups and later decide you don't want to see its popup windows after all? Firefox gives you direct access to the list of exception sites, so all you need to do is open it and remove the site: 1. 2. Click the Content icon in the strip at the top of the Options window. 3. Click the Allowed Sites button next to the Block Popup Windows check box. 4. In the window that appears, select the address of the site whose popups you want to start blocking again (see Figure 9-4). Figure 9-4: Just say "no" to popups. Select the sites for which you want Firefox to start blocking popups again. 5. Click the Remove Site button at the bottom of the window. 6. Click the Close button to close the window, and then click OK to close the Options window. The next time you visit the site, Firefox once again blocks its popups.           Chapter 10: E-Mailing with Thunderbird Browsing without e-mail is like eating peanut butter without jelly, and I would be negligent if I failed to introduce Thunderbird, a first-class e-mail application that runs on your desktop. Thunderbird and Firefox serve two different purposes, but have plenty in common. Both are produced by the Mozilla Foundation, and both share the same goal: to make your life easier. And although they are two separate products, the experience is best when you use both because they integrate well. Thunderbird is not an e-mail provider; it's an application you can use with your existing provider. If you use a Web-based e-mail program that you're satisfied with, it might not make sense to begin using Thunderbird. However, if you're currently using Microsoft Outlook, you should switch to Thunderbird because it offers superior search and spam-blocking capabilities. In this chapter, I walk