If you log on to the webmail account via a browser, do you see those ' 5 missing folders' ?

Did you try this: Right click on imap mail account and select 'Subscribe' Click on 'Refresh' Do you see those folders in the list?

If yes, select those folders and click on 'Subscribe' click on 'OK'

Hi, I've already had a look at the webmail version of the account and can't find the folders.

I think it is down to poor coding and a "not fast enough" IMAP sync back up to the server, which has led to the route to these files and folders not being written and retained before I've powered off my PC and the whole thing have fallen into a black hole.

My ISP suggested similar stuff to try and find them and offer to charge me a fee to help find them. Not happy about paying a fee to find them, as in my book, between the ISP and Mozilla's code, they are the ones that have lost my folders.

As I move on from anger and denial and into acceptance, I've learnt a valuable lesson - "trust no one with your data, single copy" and I'm moving on to making sure it doesn't happen again.

Any recommendation for how to create mailbox backups?

I also regularly back up my entire PC with Seagate Toolkit, but appears that even this overlooks AppData folders that contain sbd for my lost folders, so that was a waste of time.

Also, any idea how to get access to actual Mozilla staff help to run this past, as opposed to forum stuff?

Thanks once again, James

re: Backups

Personally, I perform a manual backup of the entire Thunderbird folder prior to any update because it is simple and quick. Not only does this backup emails, but also mail account data, preferences, address books, etc etc the lot.

• Menu app icon > Help > More Troubleshooting Information
• Under 'Application Basics' - 'Profile folder' - click on 'Open Folder'

A new window opens showing the content of the 'profile name' folder.

• Exit Thunderbird now.

• Go up the directory 3 levels to the 'Roaming' folder and copy the 'Thunderbird' folder to an external drive.

See images below as guide.

There is also an really useful addon called 'ImportExporttools NG' which offers the ability to export a folder as an mbox file - so you can perform interim backups. It also offers the ability to perform backup of a profile.

• https://addons.thunderbird.net/en-us/thunderbird/addon/importexporttools-ng/

How to install addon extension:

• https://support.mozilla.org/en-US/kb/installing-addon-thunderbird

When you move an email from one folder to another, there is communication between Thunderbird and the server for each and every email, so there is alot of communication going on when you move several emails, let alone several folders. If you have an Anti-Virus which scans files when they are opened and/or scans every file you download and upload, then there is another delay in the process.

What seems odd is the fact that those folders seem to be in new location on Thunderbird and server for a few days before disappearing or is it possible you only noticed this after a few days and in reality they had disappeared much earlier ?

Did the Anti-Virus program quarrantined those folders ? I have Anti-Virus set up to scan but it must ask me what to do because you should never allow a fix on any Thunderbird folder. So AV alerts me to a potential issue, but it allows me to sort out the problem, otherwise AV can kill an entire file containing many emails.

Have you checked your 'profile name' folder to see if the folders still exist but the mbox files that would allow access have been removed ?

For example: If I had a top level folder called 'Family' and it contained a subfolder called 'Mum' containing all emails from mum. In the Imap mail account, you would have : An mbox file (no extension) called 'Family' An index file called 'Family.msf' A folder called 'Family.sbd' The 'Family.sbd' folder would contain: An mbox file (no extension) called 'Mum' An index file called 'Mum.msf'

If I lost the mbox file (no extension) called 'Family' Thunderbird would not know about the all the subfolders in the 'Family.sbd' folder, even if the 'Family.sbd' still existed.

If this is the case, then You could access 'profile name' folder, Exit Thunderbird, copy the 'Family.sbd' folder and put it in the 'Local Folders' folder and at the same time create a new mbox file by doing the following: New > Text Document call it 'Family' It creates a file called 'Family.txt' Then rename 'Family.txt' by removing the .txt part, you will get a prompt asking if this what you want to do, so 'yes'. Now when you restart Thunderbird, the 'Local Folders' account will display the 'Family' folder and it's subfolders.

Why put it in 'Local Folders' mail account - because when you restart Thunderbird, it auto checks what is on server and 'Family' does not exist, so it gets removed from imap account.

What do you have in the 'profile name' folder > ImapMail > imap account name folder? Do you see any of those .sbd folders ?

Just be aware that when using the subscribe function, if you just check the boxes it sometimes does not action the subscribe request on my mail, I have to highlight the folder then click the subscribe button on the menu. Plus with Outlook IMAP when naming the folders it recognises folders with a slash in their name (/) but for some reason Thunderbird does not, it took me a long time to arrive at this conclusion, so be careful with folder names!