I posted this yesterday and received a response from sfhowes quite promptly. Unfortunately, Automatic Download was enabled in Thunderbird and the response disappeared into my inaccessible Inbox before I was able to read it on my ISP's web-based email. But I did find the response (without reply links) in my Inbox.msf file. sfhowes asked in the response: "Hi DBee, Is the Folder Pane visible but empty, or is it hidden (under View/Layout\)?" Answer: The Folder Pane is visible and empty. Automatic Download is now turned off so I will be able to respond to forum emails within the thread. Thanks in advance for picking this up and continuing the problem solving.