I must have hit some wrong button because I cannot return to my opening screen list of (non-deleated) emails. There are tabs across the top of (now wide screen) view screen, which represent a bunch of old, maybe archived by year, e-mails. Hitting the tabs merely brings up that e-mail, and none of the tabs seem to get me back to my normal opening screen. Closing Thunderbird does not reset anything, and turning it back on returns to the email previously on the screen, not the opening list screen.