Thunderbird stores information about emails in a number of places. There is a global index/database that the full test search uses.

There is a folder index that is mostly used to populate the lists in the user interface Then there are the actual email storage files.

The first of the things you mention is the data is in the full text database for searching. The second conversation uses the second data source, the folder index, and the display of the mail is when the last item in the set, the mail storage file, is interrogated to retrieve the email from the location stored in the folder index. It is coming up blank.

This would indicate that in all probability the first two items are "out of date" and the emails are no longer held in the folder. I have to ask, can you display the content of any emails in the same folder? That arrived after the missing ones? or before?

Thanks, Matt, for taking the time to reply and explain how things work. To answer your question -- Yes, the Inbox displays other e-mails before and after the date of the "hidden" (or missing) e-mail. Any further ideas?

Thanks again! Jonathan

At this point, and following a recent failure on my own system, I would suggest you physically remove the MSF that the system uses to populate the user interface.

Unfortunately I do not know where that file will be located as I do not know if your account is IMAP or POP, or when the mail provider is as the contents of an account are stored in a file directory that is named for the mail server name. So i have to ask more questions, or try and write a generic "how to" I tried that many years ago and it was not good, but here goes again.

1. Go to the account settings page of the account. (Right click the account name in the folder pane)
2. Select the server settings for the account.
3. The last thing in the server settings is a "local directory" entry.
4. Click browse.
5. Click in the path part of the open dialog that opens. (but not on any of the words. In a blank space at the end.) The format of the displayed text will change from the normal style and the displayed text will be highlighted.
6. Right click and select copy
7. Click on Close to dismiss the dialog without making any changes.
8. Shut down Thunderbird.
9. Using windows file explorer/manager again click in the path part of the window in the same manner used in the other dialog.
10. When the path is highlighted right click and select paste and press enter.
11. You are now in the storage location for that accounts emails and you should see and inbox.msf file ( I think you said the problem was with the inbox). Delete it.
12. Close the file explorer and restart Thunderbird and see if things would better.

Thanks, Matt, for your informative reply!!! Sorry it took me so long to write back...I've been out of commission for a few weeks.

Here's UPDATE --

(1) My e-mail is POP.

(2) Thankfully, it seems the problem might be fixed!!! (Recently my computer installed a new Thunderbird update. Do you think that has anything to do with it?) I only tested a few e-mails, so I can't know for sure if it's fixed, but I hope it's good now!

(3) QUESTION -- I followed your clear instructions and located the file, "inbox.msf". Is there any point in still deleting that now, or could it make things worse? (I know nothing about how the computer works, so I don't want to ruin anything? What does that file do?)

THANKS AGAIN, MATT!!!

Sincerely, Jonathan R.

Is there any point in still deleting that now, or could it make things worse? (I know nothing about how the computer works, so I don't want to ruin anything? What does that file do?)

It holds an index of mail in the folder and is primarily used to populate the mail list (User interface) and hold a reference to the storage location of the actual emails so they can be loaded when you click on them.

There is no point deleting it is everything is ok, but if you do, when Thunderbird starts up it will recreate the MSF so it can display the list of emails in your inbox. It is a nothing gained to delete it, but only in a few circumstances will anything be lost by deleting it. The headings customized in the lists being one of those things. However they are also lost with a repair. So it can be a fix if something is wrong. Pointless otherwise.