Start *Windows'* safe mode with networking enabled - win10 http://windows.microsoft.com/en-us/windows-10/change-startup-settings-in-windows-10 - win8 http://windows.microsoft.com/en-us/windows-8/windows-startup-settings-safe-mode - win7 http://windows.microsoft.com/en-us/windows/start-computer-safe-mode#start-computer-safe-mode=windows-7 - XP http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/boot_failsafe.mspx

Still In Windows safe mode, start thunderbird in safe mode - http://support.mozillamessaging.com/en-US/kb/safe-mode

Does problem go away? Please reply to let us know results.

I have done so to no avail.

If this is constructive it is only in one of five or six mailboxes that this is occurring. All other mailboxes are functioning fine. Contents and attachments are available. It is only in one particular mailbox that contents preceding 11/23/15 and attachments are not visible. Messages received since are fine too.

So as to expedite I'd like to ask where TB stores attachments. I find some in a eudora folder, but not all. Luckily they are not saved to the desktop as some people seem to have struggled with.

attachcments are stored WITH the mails.

is this the account imap? or pop?

The only items visible in the mailbox are the From, To, Subject and Reply to fields. There is nothing in the body. This is pop.

Please advise how to delete post.

This sounds like the same issue discussed here. Try the solutions in that thread.

I appreciate the contribution. This looked to be the solution. I located the mailbox in the TB folder, I braced myself, clicked on properties, and discovered that the size was 70kb and not in the tens of mb. Sigh. All other mailboxes are fine and in the tens and hundreds of mb.

It is inexplicable that the contents of just the one mailbox would have been discarded or moved to some labyrinthian OS location. I hope the folder was not accessed from the outside over the net. This seems unlikely given both the firewall and norton are always on.

If you discover or develop an alternative that appears to be a viable solution please advise. Thanks.