If one day of updating the index was not enough to complete, clearly a longer time would be required post the deletion of the file.

I would suggest an exemption in whatever antivirus product you use for the Thunderbird profile folder as that is a prime cause of slow everything really, especially the building of multi gigabyte files.

Thanks for your comments, @MattAuSupport.

It now looks like the indexing problems are a symptom, not a cause. I'm not sure of the underlying cause, but I have a few ideas. I'll report back if I find something.

Is there a way to get Thunderbird to show what it is doing. The Activity Manager shows some things, but not stuff like checking RSS feeds, and the console seems to only show errors. So I'm not aware of way to see what Thunderbird is actually doing when it is using a heap of CPU. Are you able to help?

Thanks!

I'm using 128.1.0esr on macOS, and Global Indexing gets stuck and never finishes on one of my locally stored folders. When I restart Thunderbird, it says determining which messages to index and gets stuck there. When I restart in troubleshoot mode, it quickly starts scanning again of that same troublesome folder, but it's always stuck at "Indexing 6 of 5052 messages in [folder name]".

Hi @user5806!

I doubt that your problem is the same as mine, so it might be worth posting it as a separate question to see if anyone can help.

I'm no expert on this, but Rebuilding the Global Database is usually the solution to problems like this.

Other things that might be worth considering are repairing the folder (see the second half of the Software interruption to the process section of the Compacting folders - Potential complications article) or moving the messages in the troublesome folder to another one.

Hope that's of some help.

Let us know how it is with 128.2.0

Thanks for following up, Wayne.

The problem is still there in v128.2, but I think that I have narrowed down the problem. It seems to be related to compacting.

As long as I click on Remind me later when I get the message about compacting, Thunderbird runs okay. I've tried this over a couple of days, and this has been consistent.

The only exception to this has been when I detached a file from an email. I got the Compact folders message, and clicked on Remind me later but shortly after this, Thunderbird became sluggish and was using a lot of CPU. As I thought that I'd have to shut down Thunderbird to get it back to normal, I tried manually compacting the folder containing the email from which I'd detached the file using (on Windows) Alt + F and then selecting Compact Folders. I though that this would reduce the chance of getting the compacting message in the future. However, and for some reason after compacting, Thunderbird returned to normal.

But just to complicate things, while writing this, I noticed that Thunderbird had become sluggish and was using a lot of CPU. So I tried compacting a couple of folders that I had used recently, with Alt + F on one folder, and by right clicking on a folder and selecting compact from the menu there with another folder, and Thunderbird is still sluggish and using a lot of CPU. So there is still something going on, or there is a folder that Thunderbird thinks needs compacting that I can't "see".

And now, since it has taken me some more time (5 - 10 minutes) to complete this message, Thunderbird has again returned to normal. I've never seen this before, even with Thunderbird using high CPU for several hours. so maybe my compacting did do something???

As I said above, if you can help me "see" what Thunderbird is doing when it is using a lot of CPU, that will probably help track down the underlying problem.

Thanks for your help.

Activity can continue after a compact is complete. This can been seen in Tools > Activity Manager.

There is nothing in the Activity Manager. Messages about compacting appear in the Status Bar, but not in the Activity Manager. Even after I get the Done compacting message in the Status Bar, Thunderbird continues to use CPU when it isn't being used, and to use CPU and run sluggishly when it is being used.

I see that Thunderbird has some logging options: https://wiki.mozilla.org/MailNews:Logging

Any suggestions on what settings I should use to see what is happening here? Compacting doesn't seem to be covered explicitly in the logging article.

Thanks