View > Toolbar.
Make sure that Standard Buttons is ticked, otherwise you will not be able to see the toolbar buttons. You may customize the toolbar.
Compose Window.
Click on the New Mail button in the Main Window. This will bring up the Compose Window.
In the Compose window, click on the View menu and check "All Headers". This will enable you to use the Bcc: box. Explanation follows later. Also make sure that the standard Toolbar buttons are shown. As before, you may customize the toolbar.
© James Nelson, 2001.