Problem. The default inbox view for the Mozilla Thunderbird e-mail client shows the sender of each message but it does not show the recipient. This is a problem if you are looking through the messages to find one that you sent to someone and copied to yourself. This is also a nuisance if you receive messages that are sent to several e-mail addresses and are trying to view and sort your incoming messages based on who the message was sent to. Nowhere in Preferences, Account Settings, or the View menu does there seem to be a way to show columns of additional information about your incoming e-mail.
Solution. In the upper right corner of the inbox listing, just to the right of Date, there is an icon that looks like a small spreadsheet with a downward pointing triangle. Click on this icon and a list of available column headings will be shown. Place a check-mark next to the columns of information you would like displayed.