What is your anti-virus software?

Try to start Windows in safe mode with networking enabled. - Win7 https://support.microsoft.com/en-us/help/17419/windows-7-advanced-startup-options-safe-mode#start-computer-safe-mode=windows-7

Still in Windows safe mode, start Thunderbird in safe mode. - https://support.mozilla.org/kb/safe-mode

Does the problem go away?

My antivirus is Microsoft Security Essentials.

I restarted Windows in safe mode and restarted TB with all add-ins disabled and it's hard to say. Windows is nearly unusable that way and it doesn't happen all the time.

So in the 2-3 minutes I spent sending test emails, it seemed better but at least once TB froze long enough for me to curse and pull up task manager and for task manager to show TB using 25% of the CPU. But that also ended very quickly, whereas the "normal" freeze lasts many seconds (10-30).

So, not sure. Seems like the problem didn't go away, but maybe it's better? Maybe I just didn't test it long enough. Either way, what does that mean?

I just re-ran the tests (sending myself a few test messages to have TB send and receive a few times) in "normal" mode, and it's about the same (no freezes). I can get the CPU to go up to 11% and it spiked to 19% but I cannot make it get to 25% and stay there for a while.

Maybe that means the problem only occurs when TB has been running for a while. I often go a couple weeks between reboots.

But maybe it just means that this intermittent problem hasn't occurred in the few minutes I've spent testing. It only happens a few times an hour, always seeming at the least opportune time.

re :I often go a couple weeks between reboots. So, when you do use this computer, the folders in that imap account need to synchronise with server to get at least a couple of weeks worth of updating.

Do you know how frequently you compact folders ? Is it set to do it automatically? Have you noticed if the cpu rise occurs when compacting is occuring or coincides with checking server for new mail or when you select a different folder?

How do you organise emails? What I mean is do you have a lot of folders to organise mail or keep loads of emails in only a couple of folders? Do you have a few/loads of subfolders etc?

On Win 7 computer, right click on imap mail account and select 'Settings' Select: 'Server Settings' How frequently do you check for new messages?

Select 'synchronisation & storage' Please tell the forum what setting you have selected. 'message synchronisating' Is 'keep messages in all folders for this account on this computer' selected or not?

click on 'Advanced' button Are all folders selected or only a few eg: Inbox and Sent?

Under 'Disc Space' What option is selected?

In your 'profile name' folder usually located here:

• C:\Users\<Windows user name>\AppData\Roaming\Thunderbird\Profiles\<Profile name>\
• click on 'ImapMail' folder
• click on imap mail account folder
• Make sure the column header for 'Size' is showing
• Please post an image showing contents of your imap mail account.

This info will help us to understand your current setup.

Windows safe mode disables anti-virus software, which is often the culprit. These are some generic suggestions to avoid problems with anti-virus software.

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

Don't let your anti-virus software scan incoming and outgoing messages.

Don't let your anti-virus software scan attachments.

Don't let your anti-virus software intercept your secure connection to the server.

Remove any add-ons your anti-virus software may have installed in Thunderbird.

Keep it working. http://kb.mozillazine.org/Keep_it_working_-_Thunderbird

And last but not least, backup your Thunderbird profile on a regular basis. https://support.mozilla.org/kb/profiles-where-thunderbird-stores-user-data#w_backing-up-a-profile

Beyond anti-virus software potentially being the culprit also see if this article helps. https://wiki.mozilla.org/Thunderbird:Testing:Memory_Usage_Problems

alanmead said

I just re-ran the tests (sending myself a few test messages to have TB send and receive a few times) in "normal" mode, and it's about the same (no freezes). I can get the CPU to go up to 11% and it spiked to 19% but I cannot make it get to 25% and stay there for a while. Maybe that means the problem only occurs when TB has been running for a while. I often go a couple weeks between reboots. But maybe it just means that this intermittent problem hasn't occurred in the few minutes I've spent testing. It only happens a few times an hour, always seeming at the least opportune time.

Toad-Hall said

re :I often go a couple weeks between reboots. So, when you do use this computer, the folders in that imap account need to synchronise with server to get at least a couple of weeks worth of updating. Do you know how frequently you compact folders ? Is it set to do it automatically? Have you noticed if the cpu rise occurs when compacting is occuring or coincides with checking server for new mail or when you select a different folder?

Thank you for your help. I've tried to answer comprehensively.

About compacting, I don't know if it's automated. There's a setting under Options > Advanced > Network & Disk Space that says "Compact all folders..." and it's always been checked. But I assumed Compacting just re-wrote the mbox file without deleted messages. I didn't think it would affect other things and I rarely compact my folders because I long ago set the limit to 1000 MB. Recently (maybe two weeks ago) I did wonder if compacting more frequently might be better and changed this setting to 100 MB. I'm pretty sure TB has compacted since then once or twice. Usually File > Compact Folders is greyed out, but I noticed in writing this that it wasn't and I compacted my folders.

It's true the CPU probably spikes when compacting, but to be honest I leave TB alone when it's doing that. Rewriting a large mbox file seems at least slightly dangerous. My problem is NOT obviously related to compacting. It seems to happen when I send or receive email. For example, it's not uncommon for me to send an email and then open Sent and forward the email to a colleague. Frequently, this workflow encounters the freeze. The other freeze that happens is I'll be typing a long email (or really doing anything) and new mail will come in and TB will freeze.

How do you organise emails? What I mean is do you have a lot of folders to organise mail or keep loads of emails in only a couple of folders? Do you have a few/loads of subfolders etc?

Well, I don't organize. I annually select all the emails in my inbox that are more than a couple years old and move them to another folder. I have massive InBox and Sent mailboxes and several fairly large folders.

I know some people think this is bad, and I agree that I suspect that this contributes to my TB problems, but the projects I work on take years and I don't care to spend a lot of time to organize emails and I don't like deleting. Being able to check old emails or search for an email about a topic has been a lifesaver. The Windows 7 machine has 16GB of RAM, four cores, and 1TB of disk space. I'd like to think it can handle GB inboxes. And, again, although I've had the same habits for a couple decades, the problem has grown and TB is just having these problems recently. Also, the freezing is worse on this relatively capable machine than on lesser machines.

On Win 7 computer, right click on imap mail account and select 'Settings' Select: 'Server Settings' How frequently do you check for new messages?

Check for new messages every 10 minutes

Select 'synchronisation & storage' Please tell the forum what setting you have selected. 'message synchronisating' Is 'keep messages in all folders for this account on this computer' selected or not?

I don't recall changing any of these settings:

Keep Messages in all folders for this account on this computer (CHECKED)

click on 'Advanced' button Are all folders selected or only a few eg: Inbox and Sent?

Most of the folders are selected for download. I didn't count, but there are about 60 folders across six accounts and perhaps 50 of them are checked.

Under 'Disc Space' What option is selected?

Synchronize all messages locally regardless of size (SELECTED) (Don't download... is NOT checked) Don't delete any messages (SELECTED) Always keep starred messages (CHECKED)

In your 'profile name' folder usually located here:

• C:\Users\<Windows user name>\AppData\Roaming\Thunderbird\Profiles\<Profile name>\
• click on 'ImapMail' folder
• click on imap mail account folder
• Make sure the column header for 'Size' is showing
• Please post an image showing contents of your imap mail account.

This info will help us to understand your current setup.

I have six accounts. I attached a screenshot of the most-used (oldest) account with the largest inboxes. Some of them are really large. My inbox used to be much bigger but I was taxing my ISP's mailserver.

I suspect that you're going to tell me that my mailboxes are too big, but the mail server (which switched to maildir a few years ago) handles this load fine and TB has worked fine with really big mailboxes in the past. Also, I'm not expecting magic, just for TB not to freeze and not respond for 10-30 seconds. It used to work fine, and I want it to work like that again.

Thanks again for your help with this problem.

christ1 said

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 Don't let your anti-virus software scan incoming and outgoing messages. Don't let your anti-virus software scan attachments. Don't let your anti-virus software intercept your secure connection to the server. Remove any add-ons your anti-virus software may have installed in Thunderbird.

Thanks for your help with this. I had previously (months or years ago) suspected my antivirus and I excluded a folder. A screenshot is attached. I think this should prevent MSE from interfering, but I'm posting it in case you notice something I don't. I don't think MSE or any other vendor has installed any plug-ins, etc. AFAIK, disabling "Real Time Protection" prevents this stuff and before I posted here I disabled MSE real time protection and observed a freeze, so I don't think MSE is the problem. Unless you see a flaw in my reasoning. I'm not running any MacAfee crapware or anything like that.

Keep it working. http://kb.mozillazine.org/Keep_it_working_-_Thunderbird And last but not least, backup your Thunderbird profile on a regular basis. https://support.mozilla.org/kb/profiles-where-thunderbird-stores-user-data#w_backing-up-a-profile Beyond anti-virus software potentially being the culprit also see if this article helps. https://wiki.mozilla.org/Thunderbird:Testing:Memory_Usage_Problems

I'll have to check out these. I've read part of the very long "memory usage problems" article. I have 16GB of RAM and TB consistently uses 1-2GB. Oh, and I'm using 32-bit TB... Maybe it can only address 2GB? I hadn't considered that...

I'm using 32-bit TB... Maybe it can only address 2GB?

No, that isn't a problem with 32-bit.