I have located a bug regarding this - is this the same bug you see? https://bugzilla.mozilla.org/show_bug.cgi?id=1779273

Please check other reported bugs to see if one is you: https://bugzilla.mozilla.org/buglist.cgi?quicksearch=%3Athun%2Cmailn%20compact%20delet&list_id=16148623

Thanks Toad-Hall I attach a screen dump to see the size of the compaction problem. Don't want to stop using TB as I have been using it for 20 odd years. Maybe you can throw some additional light on the issue?

Is version 102.0.3 better?

Feedback: Now using 102.0.3 I can manually compact folders. With 'Folder Pane columns' enabled and 'Size' selected, I can see the size reduce when I manually compact.

I switched off the auto.

Thanks Toad-Hall and Wayne Mery but no problem not solved now suggesting that I will recover 521GB of disk space. Looks like I will have to migrate away from TB to Outlook.

Please enable the 'Folder Pane Toolbar' and select 'Size'. 'Menu icon > View' > Toolbars' > select 'Folder Pane Toolbar' Then use small icon on the right to select 'Size' column - see image below as guide. The image is an older version, but everything is the same.

Please post an image showing the Folder Pane, so we can see each folder and it's size.

Then do the following to see if there are any nstmp files in profile.

• Menu icon > Help > More Troubleshooting Information
• Under 'Application Basics - half way -Profile Folders - click on 'Open Folder'

• Exit Thunderbird now. - this is important.

• If you have a POP mail account click on 'Mail' folder to see contents.
• If you have an Imap mail account click on 'ImapMail' folder to see contents.

• Create a folder on the Desktop - call it 'TB Backup'
• Make a backup copy of the pop or imap mail account name folder - put it in the 'TB Backup' folder temp backup.

• Back to the original - Click on the mail account name folder to see contents.

Do you see any files called nstmp ?

• If yes, move those files into the 'TB Backup' folder.

• Delete all files that have a .msf extension.

If you have any folders with a .sbd' extension :

• Click on *.sbd folder to see contents and Delete all files that have a .msf extension.

When you are certain you have deleted all the files with a .msf extension....start Thunderbird.

Allow a little time to ensure all accounts, folders etc are up and running Start with the 'Drafts' folder:

• Note the size of the 'Drafts' folder
• Right click on 'Drafts' folder and select 'Compact' - does the 'Size' reduce ?

Now deal with the 'Junk/Spam' folder:

• Note the size of the 'Junk/Spam' folder
• Right click on 'Junk/Spam' folder and select 'Empty Junk'
• Right click on 'Junk/Spam' folder and select 'Compact' - does the 'Size' reduce ?

If the answer is yes:

• Note size of 'Inbox'
• Right click on 'Inbox' and select 'Compact' - does size reduce ?

Please report back on results. Please post an image showing the Folder Pane, so we can see each folder and it's size. It means we can see the effect of instructions on the folder Pane and compare size for folders.

I have located a bug regarding this - is this the same bug you see? https://bugzilla.mozilla.org/show_bug.cgi?id=1779273

Note, that bug is "fixed", but it isn't yet in version 102 or beta. I anticipate it being in 102.1.1 in 2-3 weeks.

Thanks Toad-Hall and Wayne Mery but no problem not solved now suggesting that I will recover 521GB of disk space. Looks like I will have to migrate away from TB to Outlook.

The numbers may sound scary, but this is really a benign issue that doesn't adversely affect the operation of Thunderbird. Unless you are running out o fdisk space or seeing other major issues, you shouldn't need to abandon Thunderbird.

Thanks Wayne Mery & Toad-Hall the screen dump you attached was the same but the size was totally different from the 614mb shown. My dump shows 595GB which is the size of the SSD, but the cumulative total of TB folders is 800mb or so. Hence I am reluctant to do any compacting. I note that you say there is a fix. I await version 102.1.1 in anticipation. If that fails I will use the advice given by Toad-Hall. Thanks again both for useful information.

Thanks Wayne Mery. I am now running Thunderbird version 102.2.0 and the compaction problem has not been fixed. My message now reads that compaction will recover 1.1 TB of space larger than my disk. I had hoped that this would have been resolved as you suggested in version 102.1.1 but not to be. Probably don't consider it important enough to warrant a fix?