Try to start Windows in safe mode with networking enabled. 7-advanced-startup-options-safe-mode#start-computer-safe-mode=windows-7

Still in Windows safe mode, start Thunderbird in safe mode. - https://support.mozilla.org/kb/safe-mode

Try again to repair the folder. Be prepared that messages will be gone, so make sure you do have a backup of your Thunderbird profile. You may only be able to restore messages from a backup. https://support.mozilla.org/kb/profiles-where-thunderbird-stores-user-data#w_backing-up-a-profile

Thanks for taking the time to reply. I just did what you suggested and it did not result in my being able to see the missing emails. When the folder was attempting to build summary file the status bar only went up 1/5 of the way and after 3 or 4 minutes with no movement the process stopped but no additional emails were showing. Only 3,221 of the roughly 13,000. The folder is still 380MB so the emails are there but just not accessible. Any other suggestions?

Peace, Greg

What is your account type, POP or IMAP? Is the troubled folder a local one, or on the server?

My account is POP and the folder is local. I was able to restore a fairly recent back up of the folder however I am still missing a substantial amount of the emails and they are all business related. Thanks, Greg

Is the troubled folder your Inbox?

In any case, you can try to move messages to a different local folder. You may actually want to create one for that purpose. When moving messages, select the messages to be moved - right click - Move To. Pick the previously created folder as destination. Move messages in smaller batches, not all at once.

Once all (visible) messages have been moved, compact the troubled folder (right-click the folder - Compact). Then check the size of the folder and post the result.

The folder that has been effected is not the InBox which I tend to keep empty.

I went ahead and moved over the 3200 emails that were visible and went to compact it and said I did not need to but showed that 69MB of space saved. When I look at that folder on my server it is showing there is 0KB now and the folder where I moved the visible emails to is showing 69MB.

That suggests the emails are gone however that folder has consistently been showing that there is 380MB worth of data in it. Is there really nothing left in that damaged folder or is data so damaged it cannot be seen?

Thanks again,Greg

When I look at that folder on my server it is showing there is 0KB now

I don't understand 'folder on my server'. Your account is POP, were talking about a troubled local folder, which is not Inbox. How can you see that folder on a server in the first place?

From your description it isn't clear to me which folder exactly you're talking about. I'd assume the troubled one, which advertised a size of 380 MB before. After moving out the visible messages and compacting it, it now shows a size of 0 bytes? If so, the process cleared the corruption, and the missing messages are gone for good. As stated before, you'd need to restore them from a backup.

Anti-virus software is the most likely cause for Thunderbird mail file corruption. To avoid this in the future follow these general suggestions.

Create an exception in your anti-virus software for the Thunderbird profile folder, so that the anti-virus real-time scanner will not scan it. http://kb.mozillazine.org/Profile_folder_-_Thunderbird

Don't let your anti-virus software scan incoming and outgoing messages.

Don't let your anti-virus software scan attachments.

Don't let your anti-virus software intercept your secure connection to the server.

Remove any add-ons your anti-virus software may have installed in Thunderbird.

Create backups of your Thunderbird profile on a regular basis. https://support.mozilla.org/kb/profiles-where-thunderbird-stores-user-data#w_backing-up-a-profile

Keep it working. http://kb.mozillazine.org/Keep_it_working_-_Thunderbird

By my server I mean my computer. When I look at the troubled folder (which is not the InBox) on my computer it is showing 0KB however I only moved over 69MB (the visible emails) of the 380MB. I did a back up of that folder prior to moving over the 69MB and then compacting however that folder is still corrupt so restoring it puts me right back where I was.

My anti-virus has never scanned emails.

RE: I was able to restore a fairly recent back up of the folder How recent was this backup - was it done prior to all the crashing/freezing troubles?

Using the backup did not make emails reappear. Was this a backup of mbox file done prior to all of these troubles?

Did you exit Thunderbird first before copy pasting the backup file into the profile folders? If Thunderbird was not closed then adding the file in profile folders would not work. Presuming Thunderbird was closed prior to adding backup file.

I presume you still have a copy of the backup 340MB file stored perhaps on an external device or desktop.

Create a new folder called 'TB' on your desktop. Put a copy of the backup mbox file in the 'TB' desktop folder. You are going to work off a copy of the backup, so keeping the original backup as is, unaltered.

Access the 'TB' folder and open the copied backup mbox file using 'Notepad' or similar text editor program.

Suggest you break up that file into at least four. So the quick way would be to create four copies of same file. Then access each in turn and delete sections to reduce the file. In the first, keep the first quarter and delete the rest. In the second, delete the first quarter, then remove the last two thirds. So keeping the second quarter. Do similar in the others keeping the third quarter in one and last quarter in the last copy.

Now you should have four mbox files, each containing a different quarter of the original.

Emails are listed one after the other in the order downloaded, so the oldest will be at the top. Make sure you have completed emails...as indictated below, you now know what the first line is, so therefore you can tell the end of an email.

Each email starts with the following lines: This is just an example:

• From - Fri Jul 29 16:13:05 2016
• X-Account-Key: account1
• X-UIDL: UID7025-1224250522
• X-Mozilla-Status: 0001
• X-Mozilla-Status2: 00000000

then there will be a load of header info followed by the email itself perhaps it will be twice , once in plain text and once in html. If an image was attached then you may see a load of jabber of letters and numbers after the email.

Now for each of the four separate section copies: starting at the top:, use the 'Edit' > 'Find' tool to search for each X-Mozilla-Status: line Make sure each X-Mozilla-Status: line has the number 0001 Make sure there is two blank lines between emails.

Make sure Thunderbird is closed, it must not be running. Copy paste those four files into the profile folder.... /Mail/mail account name, so it is now in the profile. Start thunderbird. the .msf files will be auto created. Do you see those files as new folder in the 'Folder Pane.? Do you see any of the emails?

The back up folder, which I referred to earlier that was restored, was from several months ago and before my current issues. I am able to see all of those emails however since it is a back up from several months ago I am still missing roughly 1500 emails.

I still have a copy or back up of the 380MB folder which contains all of the emails of which only 69MB were able to be viewed. I have tried to open the 380MB file before I posted here and it won't even open in Notepad. I had my IT people out and they took a copy of the folder to see if they could access it but so far I have heard nothing.

Thanks

All I can imagine is that ONE e-mail message in the middle of the file is corrupted.

I suggest you use a text editor and try find the text of the last visible message (backwards maybe?) and the next message is the culprit.

Delete the message and try again.

I assume you know how to make a backup copy because of what you've said before.. Quite a hard job to pull but maybe it is possible to save the folder.

Thanks for the suggestion. I do have a back up copy of the corrupted folder and can make another. I had tried opening it in Notepad and it was not able to open it. Since I have never used a text editor is it possible the file can be opened even if it did not open in Notepad?

Greg

Try downloading Notepad++ UltraEdit would be best but its not free. But handles large files faster than Notepad++

I'm hoping that once you split the files into four smaller ones, you might be able to determine where any bad emails reside.