Unfortunately, bulk mail move of thousdands of messages at a time doesn't work very well.

I've not tried it myself, but one possible approach is try moving groups of messages again, and then use https://addons.mozilla.org/en-US/thunderbird/addon/remove-duplicate-messages-alte/ to remove duplicates in the target archive folder

Thanks for a reply but it doesn't address my particular problem. I don't move many thousands and the method has worked fine in years past. The messages I selected for a move are no longer visible for a re-try. How do I make them visible?

right-click on folder > properties > repair

Thanks again, Wayne. I had tried this before and still no effect. Any more suggestions? Dennis

If I want to move several emails from an imap mail account folder to an account outside of imap account eg: 'Local Folders' mail account, then I usually follow this proceedure.

Synchronise folders for offline use to ensure I had full up to date copies stored in my profile and not just headers. Then in 'Offline' mode - I do not want any synchronising of that folder whilst I'm using it - I use the 'Copy' not 'Move' method. If I copy and things go wrong, then the original is still in the original folder. Once all emails are ok in 'Local Folders' - I test by viewing a few random emails. I've always found all is ok by this method.

Then I can delete the ones in imap folder. Go back to online mode and server gets updated.

re : I think offer to 'compact' came up and I accepted A possible reason for loss of emails. Compacting removes all traces of marked as deleted emails. If there was some corruption of Inbox file then it is possible that Thunderbird couldn't figure out where a message ended anymore and deleted both marked as deleted and good emails. You'll typically run into this only with the Inbox folder. It's much more vulnerable to corruption because it frequently has both lots of messages and a high percentage of deleted (but not visible) messages especially if you do not compact on a regular basis and have a habit of storing a lot of emails in the Inbox.

Q: Do you have a recent backup of profile name folder? Q: Is this a gmail account ? Q: Is this a pop or imap mail account ?

In your profile: Do you have any *.mozmsgs folders containing *.wdseml files. These folders and files are created in a manner that allows Windows to index them.

If yes: Copy the *.wdseml files from the *.mozmsgs folder in your profile to a new folder eg: on desktop. Change the file extension from .wdseml to .eml This means each email is now a separate .eml file. Download and install the addon: https://addons.mozilla.org/en-US/thunderbird/addon/importexporttools/

Use the ImportExportTools Add-On to import the missing messages back into Thunderbird. Right click on folder > ImportExporttols > Import Messages locate fodler string .eml files Press 'Ctrl' key and select to highlight .eml email files. click on Open.

This will import the .eml files into the folder.

Many thanks. Toad-Hall. A lot to think about and try, but still no solution.

I suspect triggering 'compact' probably did cause the problem. I kick myself!

I don't seem to have a profile but have now created one. It shows in C:\ users-----/Roaming/etc. Is that where i would have found *.mozmsgs? I searched all of 'My Computer' and such folders were not found.

So, I'm open for any further suggestions.

Toad,

Is this a case for editing the msf file to fix the X-Mozilla-Status flag values? I was looking for a previous example to quote from but ran out of time.