What's not clear to me is how you managed to accumulate that many messages in Inbox, and why the junk messages haven't been sorted out yet. Didn't you access that account for the last 10 years?

Presumably the size of your Inbox file is significant. So it will take time for the anti-virus software to scan the file after each read/write operation. Possibly your anti-virus software cannot cope with scanning Inbox in time due to the size of the file, and the spam detection process stops.

Also, anti-virus software can cause corruption of mail files. So in worst case you can loose the entire Inbox, because you didn't follow best practice. http://kb.mozillazine.org/Keep_it_working_-_Thunderbird

It's therefore recommended to create an exception in your anti-virus software for the Thunderbird profile folder, so that the anti-virus real-time scanner will not scan it. http://kb.mozillazine.org/Profile_folder_-_Thunderbird

Make sure to compact Inbox after spam messages have been removed, so that the size of the file Inbox is reduced in the end. http://kb.mozillazine.org/Compacting_folders

I don't think it's my virus scanner. The behavior is that when I run the junk filtering on my inbox I can see it quickly going down the list of emails and marking a lot of them as spam. Then after a minute or two it just stops.

I use this inbox everyday for work and have had it for about 8 years. I've tried turning off my virus scanner while trying to spam scan the entire inbox but that doesn't help. The scanning just stops completely after a few minutes or running pretty fast. The size of just the inbox (not what's in the folders) is 9.1 GB.

Is there a way to debug the script that processes the inbox? I assume that the messenger/content/junkCommands.js script is what's actually doing the processing. Does that have any debugging settings that might help me determine what's going on to cause it to just stop?

I had Thunderbird configured to check for new messages every minute. I tried turning that off and it seems to have run for a bit longer this time but it still stopped after about 5 minutes. When it's running it's flying down the list of messages marketing them as spam and while it's doing that the bottom left status bar is indicating the percentage complete or indicating that it's downloading messages. Once it stops no more messages appear in the bottom left status bar.

Any suggestions at this point?

Thanks.

If spam messages are being downloaded in the process your email provider may limit the amount of data being transferred from the server.

I run the email server and there are no limits on the amount of data that can be transferred from the server.

Reduce the size of your inbox by about half and I think you will stop having issues. A 9Gb inbox is simply to big for any software to manage properly. limit your self to around 4Gb unless you want to have issues.

Remember most of these mail programs (read all I think) were written when a large email account held 25mb of mail. So make it bigger usually turns out to be break it.. Outlook also has huge issues with PST files as they grow over 15Gb but that is the entire outlook mail store. Thunderbird starts to show cracks around 4Gb per folder. While the developers have been working on removing what was a hard limit of 4Gb per folder, I doubt it will ever be perfect.

I suggest you look hard at archiving. a nice mostly automatic way to manage folder sizes, bu placing mail in year sub folders.

Are the sizes you're referring to the size of what Thunderbird is using locally on my desktop? Or the size of the email as it sits on the server? The 9.1 GB size I had mentioned was simply the size of the email on the physical email server. The size of my Thunderbird profile folders (which includes several other email accounts is only 0.5 GB.

Is this really a Thunderbird question? To me it sounds like the server hasn't been regularly "cleaned" of spam and deleted mails. What's your email server program?