Compact does not delete mail.

That they are reported in activity manager, I would guess that your removed them either on another device or the google web site and that change has been synchronized to Thunderbird.

Yes Mark - in theory it should not have BUT it has. 14 of the missing emails , even if I did had sync with another device, these ones I would not have deleted as I File those into a folder for back referencing

There s no point continuing this conversation as you are unable to accept the fact compact can not delete mail.

Perhaps another possibility (if this is a gmail account) is that AV trashed the important folder.

But to get back to compact, was this an automatic compact, or a manual compact?

Hi Wayne, Yes it is a Gmail account. I don't understand about "AV trashed the important tagged items" What occurred was - I was working on one screen and the screen with the emails up on the request on "compact" came up and I allowed it to do so. One minute emails tagged Important (green colour) were there and the next they had disappeared after the compact process was completed. I know that what happened, it is frustrating from the business side of operations, but it has and I do not understand why or really what happened. I have now disabled the auto "compact" request. As to loose emails that one has not chosen to delete is not good. Was just putting the incident to Mozilla for information.

Do you mean 'tagged' as important OR emails put in gmail 'Important' label/folder.

Background info: When you delete a message, it is not actually deleted. It is hidden from view and 'marked as deleted'. This is done so that you can retrieve an accidentally deleted email. when you compact, a copy of the file is created and those 'marked as deleted' emails are removed, then file is recreated.

If the folder was corrupted in some way, either through eg: a lack of compacting maintenance or AV had performed a scan on it and caused some corruption. It is possible thunderbird could either no longer detect the correct start and/or end of 'marked as deleted emails or AV had caused corruption on file and therefore lost emails.

Have you ever performed a backup of your emails so you had a copy of the backup on your computer?

If you access your Profile folders imap mail account, do you have any folder or file called *. mozmsg? If you had emails in 'Important' folder perhaps it would be called 'Important.mozmsg' ?

Toad-Hall, you are magnificent. You have paid attention to what my problem was and communicated to me in terminology that I could understand then apply. I really appreciate your time and effort.

Answer to question No 1. I had Tagged" them (coloured highlights) not placed them into any folder at that time.

No 2. "Background info" In reading and slowly comprehending your information then following though with that - you have helped me find the "missing/deleted" emails. They had been moved over to the "deleted folder" as a result of the compact action, I have now retrieved them.

No 3. Backing up emails. No I have never backed up emails. BUT with your explanation/advice I shall do so.