1) Thank you again, Stans. After your most recent explanation, I did eventually find most of my email messages in the backed-up folder. But I can't find the attachments to those emails. 2) My difficulty in finding the emails themselves was because the immense amount of information that is added to the text of the emails – such as: X-Account-Key: account1 X-UIDL: 15581 X-Mozilla-Status: 0011 X-Mozilla-Status2: 00000000, etc, etc, etc. I assume this is the result of the MBox format, but there is so much of it that one doesn't see the the emails themselves until one knows where to look. 3) Please tell me if I have missed finding the attachments or if they really aren't there.

The attachments are there, encoded in text form. When Thunderbird (or any other program that can read the mbox format) loads the messages, it also decodes the attachments from text form to their respective formats.

4) You say “Opening the mbox file using a text editor is not an intuitive way of reading your backed up messages as you'll soon find out after you open one using Notepad.” But isn't Notepad a text editor?

I also said, "It's a plain-text file that you can open using a text editor like Notepad."

5) If the backed-up folder is restored, will it re-format the emails into the original Thunderbird (.eml) format?

Thunderbird's default format is mbox (NOT eml) so NO, it won't reformat the messages from mbox to eml.

If you prefer to save or backup your messages in eml format instead, then you can do so by selecting the messages you wish to save and use the Save As > File option in Thunderbird's menu, or press the Ctrl+S keyboard shortcut, then specify the target location. It's tedious if you have several folders of messages to backup, since you literally have to open each folder, select messages and specify target locations. This is why it's much easier and faster to simply backup the Thunderbird (profile) folder and keep it for future restoration if the need ever arises.