It sounds like your mail files were already corrupted prior to compacting.

Depending on the corruption compacting may erase messages from the affected folder which cannot be recovered anymore. In that case you'd need to restore them from a recent backup done prior to the corruption.

Corruption is often caused by anti-virus software messing with Thunderbird mail files. It is therefore recommended to create an exception for the Thunderbird profile folder, so that the real-time scanner won't attempt to scan the profile with your mail.

For more information on the profile location see http://kb.mozillazine.org/Profile_folder_-_Thunderbird

In the future create a backup of your Thunderbird profile folder on a regular basis. https://support.mozilla.org/kb/profiles-tb#w_backing-up-a-profile

Also see http://kb.mozillazine.org/Keep_it_working_-_Thunderbird

I wonder...may I have your thoughts on the following...

Some months ago, Thunderbird did a major ??something?? Each time I opened the program, it forced me to ____.

It was a request that seemed so intrusive / unreasonable / complicated. Also it would not allow me to move pass that point until I satisfied that request.

After a few days of being blocked, I closed Thunderbird and abandoned it. Instead I used my webmail.

At the time, when Thunderbird was blocking my access, I'd hired new staff. Half of our back and forth was in Thunderbird folders and half continued in new ones created in webmail.

Those are the 4 folders...in both Thunderbird and webmail...that are missing.

Finally time went on and I re-opened Thunderbird. It had settled down and was no longer asking the original aggressive request.

I attempted to create new folders for the 4 new staff but Thunderbird will not allow me to do that. I'll enclose Thunderbird's error report for when I try to recreate one of the missing folders.

Do you still think it's a corruption from an outside source? I think it's a Thunderbird issue...along with their new demand to compact. which I won't touch for fear of loosing other folders.

Thank you for your time...

Compacting is not something to be ignored. All emails that get deleted are hidden and marked as deleted, they are still in the file taking up space.

I've just helped someone who could no longer delete batches of emails and needed to compact the file.

Emails are not stored in separate files, they are written to one text file called Inbox. As they download they are written below the previous email.

It's a bit like have one single document and imagining each email as a paragraph.

It is a better idea to not allow AV products or products like CCleaner to have any access to Thunderbird files and folders. It is advisable to compact folders on a frequent basis. In particular for Inbox, Junk and Drafts as they can accumulate the majority of 'marked as deleted' emails. Keep the Inbox low in numbers and use other folders for storage.

re It was a request that seemed so intrusive / unreasonable / complicated. Also it would not allow me to move pass that point until I satisfied that request. Sounds very odd indeed, but without knowing what that was, it is impossible to guess.

re : I also checked via my online email and those 4 folders are also missing. Did you see if they were in the webmail 'TRash' folder ? I suspect they are not in any Trash anywhere.

Are those 4 missing folders still listed when you check the 'Subscribe' list?

• Right click on mail account in Folder Pane and select 'Subscribe'.
• Is it possible to select them and clickon 'Unsubscribe', click on OK ?

Are those 4 missing folders still listed when you check the 'Settings' synchronise options?

• Right click on mail account in Folder Pane and select 'Settings'
• select 'Synchronisation & storage'
• Click on 'Advanced' button

Are they listed and selected? Is it possible to uncheck those folder or are they missing? If you do make any changes click on 'OK

And these missing folders and hundreds of my emails that are missing are exactly why I refuse to compact my folders. I lost so much research, I can't begin to tell you how much information I lost. Why are deleted emails and deleted folders kept if we've said they can be deleted? I know what I want kept and what I don't need any longer. I don't want Thunderbird to arbitrarily decide what it wants to keep.

morlaine, please start a new topic for your problem. https://support.mozilla.org/questions/new