If you were on a current version of MacOS I'd suggest updating to Thunderbird 128.

That is not an option for you, see I suggest looking at https://wiki.mozilla.org/Thunderbird:Testing:Memory_Usage_Problems

I don't recall any problems with memory-use getting out of control... just the processor usage going rampant. It never gets to 200% so there is still some available CPU power from my Core2 Duo and things don't necessarily feel slow until I try doing something more intensive.

Right now, Thunderbird 115.10.1 is using 492MB RAM and 0.0% CPU (though goes to 3.3% when checking for new messages). With all my other apps running, total memory pressure is 31%. I will do another test by closing the window and waiting for CPU usage to go wild and then I will check RAM usage and report back.

What is the word on version 116?

Thunderbird has gone out of control again. CPU usage is 113%, memory was up to 612MB when I noticed, and has climbed up to 682MB after another 10 minutes or so. Now it is 713MB. Memory pressure is still around 30-31%. I guess I will have to look deeper into this problem on Monday when I return to work.

Perhaps instead of second guessing the expert that advised you about what is, or is not, a memory problem you should utilize the information and undertake the steps the Wiki suggests.

What is the word on version 116?

Both Firefox and Thunderbird 116.0 and later versions requires macOS 10.15 (ten.fifteen) or later to run.

John Gilbert said

What is the word on version 116?

Both Firefox and Thunderbird 116.0 and later versions requires macOS 10.15 (ten.fifteen) or later to run.

Version 116 of Thunderbird was never released. It goes Version 115 then Version 128.

In Thunderbird's ESR release cycle version 116 never made it past a beta release.

James said

John Gilbert said

What is the word on version 116?

Both Firefox and Thunderbird 116.0 and later versions requires macOS 10.15 (ten.fifteen) or later to run.

Version 116 of Thunderbird was never released. It goes Version 115 then Version 128.

In Thunderbird's ESR release cycle version 116 never made it past a beta release.

I am aware that Thunderbird versions from 116 to 127..0 were Beta test builds, just saying that both Firefox and Thunderbird from 116 and on requires macOS 10.15 at minimum to run.

Perhaps instead of second guessing the expert that advised you about what is, or is not, a memory problem you should utilize the information and undertake the steps the Wiki suggests.

Likely the reporter doesn't realize the wiki is mostly about general performance, so I don't think the reporter is second guessing but merely restating there isn't a memory issue.

Matt said

Perhaps instead of second guessing the expert that advised you about what is, or is not, a memory problem you should utilize the information and undertake the steps the Wiki suggests.

Likely the reporter doesn't realize the wiki is mostly about general performance, so I don't think the reporter is second guessing but merely restating there isn't a memory issue.

I am not second guessing anyone's advice... merely reporting what I think might be useful information based on my experience. The article I was referred to began by talking about poor performance due to memory problems. The computer's performance had not felt sluggish, so wasn't sure if that article was relevant to this specific issue.

The article was also rather lengthy and I did not have time to complete the troubleshooting steps before the end of my work week. I will be resuming those troubleshooting steps today now that I am back to work (where the problem exists).

I hadn't previously thought it to be a memory issue, but my observations on Friday do seem to support that idea. A well-behaved Firefox uses less than 500MB memory. Once it starts to misbehave, memory usage did start climbing. It was over 725MB when I stopped it. Anyway, I will be reporting back after I get through those troubleshooting steps in that article. Thank you, Wayne and others.

Matt said

James said

John Gilbert said

What is the word on version 116?

Both Firefox and Thunderbird 116.0 and later versions requires macOS 10.15 (ten.fifteen) or later to run.

Version 116 of Thunderbird was never released. It goes Version 115 then Version 128.

In Thunderbird's ESR release cycle version 116 never made it past a beta release.

I am aware that Thunderbird versions from 116 to 127..0 were Beta test builds, just saying that both Firefox and Thunderbird from 116 and on requires macOS 10.15 at minimum to run.

This is interesting. Did I somehow end up on the development release cycle? My iMac is running macOS 10.13 and Thunderbird 115 is suggesting that I update to version 116 even though it doesn't show up on the release notes page of the Mozilla site. See attached screenshots.

Please visit Help > Troubleshooting Information. What is shown for "Update Channel"?

Please visit Help > Troubleshooting Information. What is shown for "Update Channel"?

Update Channel: release

Troubleshooting Mode did not correct the problem. Memory started out around 239MB and stayed there for at least 10 minutes while processor usage dwelled around 1% or less. I left the computer for 10-15 minutes and the screensaver was on when I returned. After clearing the screensaver, I could see that Thunderbird was behaving normally. I have iStat Menus running, so I can see activity loads at-a-glance. I also have the Activity Monitor window open during this test.

I again left the computer for another 10-15 minutes and returned to a screensaver. This time Thunderbird was running rampant. It was above 400MB when I started this post, and it is currently at 508MB and climbing.

I will look at next steps in that troubleshooting article.

Currently at 525MB.

I have done some more troubleshooting steps suggested in the article. I have yet to try Safe Mode (or Extensions Off or whatever it is called in macOS these days) because this computer sees regular business use other than checking email.

Some things that I have tested/checked that made no difference: - Hardware Acceleration Off - Set new mail check intervals a little different for each of my three accounts (3 minutes, 5 minutes, 8 minutes) - Gmail account automatic check for messages and PUSH all turned Off - Offline Mode - Mac Firewall Off - Antivirus Off - Mac Time Machine is already Off - Spotlight privacy turned on for the entire startup disk (I don't use it anyway) - Thunderbird Preferences set to not use Spotlight (it was already Off) - Checked Advanced Preferences for Spotlight options. It appears to not be using Spotlight. mail.spotlight.enable:false - Contacts List is very small (18 contacts) - No proxy ever used - Thunderird profile is on local drive within User folder of the startup disk. - Disk Utility First Aid passes inspection - No RSS feeds used - No Calendars used - No Newsgroups used - No Virtual Folders used - No Filters used - Available HD storage is almost 20GB - View > Toolbars > Status Bar Off/Unchecked

I tried removing my Gmail account from Thunderbird and the problem was still present.

Then I moved the Thunderbird folder (~/Library/Thunderbird) to my Desktop. I started Thunderbird and was greeted by the window that suggests setting up an email account. At this point, I declined it and ran without any accounts. Closed the window and let it run in the background for about an hour with no problems.

Then I set up my Gmail account, closed the Thunderbird window and let it run in the background for about an hour with no problems.

Then I renamed the new Thunderbird folder to "Thunderbird new" and moved it to my Desktop, moving the original Thunderbird folder back to my Library. Started Thunderbird, saw all three accounts were listed, closed the window and let it run in the background for an hour with no problems. I thought for sure the problem would return because of some corrupted file in my original Thunderbird folder, but it ran flawlessly.

At some point, Thunderbird decided to download the update to 115.15.0esr. I have not restarted yet, so it is still running as 115.10.1. This has me wondering if the auto-update setting was the cause of the problem since I had that turned off previously. I don't know of any way to check that now that the update has already been downloaded and is ready to install automatically the next time I restart Thunderbird.

I also find it strange that Thunderbird had previously been suggesting that I update to version 116. Thoughts?

This is interesting. Did I somehow end up on the development release cycle? My iMac is running macOS 10.13 and Thunderbird 115 is suggesting that I update to version 116 even though it doesn't show up on the release notes page of the Mozilla site. See attached screenshots.

At 115.10, the update system forces users through a dance of two updates to move users from "release" channel to "esr" channel. And it is possible for version to appear as 116.

I have apparently spoken too soon with regards to the old Thunderbird folder not being a problem. Memory and CPU have gone awry again.

I will re-evaluate things on Monday.

Thanks. Unless memory goes above 1gb I think you can focus completely on CPU.

Thanks. Unless memory goes above 1gb I think you can focus completely on CPU.

I left TB running with the window closed over the weekend. This morning memory usage was at 1.79GB and CPU usage was at 114%.

My next tests included moving the Thunderbird folder with my profile out of my user folder on my Mac and starting fresh with the defaults. I ran Thunderbird for a day without any email accounts setup -- no problems. Then I added one of my email accounts and ran it for a day -- no problems again. Repeated that with my other email accounts -- no problems.

Something in my original Thunderbird folder is causing the issue to appear, but I am not sure what. Comparing the two folders, I can see that my old folder contains extensions. These are all themes to change the color scheme/style of Thunderbird. There were a handful of these (looks like 8, though only one has a human-readable name) and none of them were actually active. I had tried them and decided I preferred the default appearance. Could these be causing the problem despite being unused?

One more difference is that the old folder contains a Microsoft Outlook email account that I haven't used in more than a year. It had been disabled for a long time. I had no reason to add it to my new profile. I don't see why that would cause this problem, but I suppose anything is possible.

Thunderbird has been running flawlessly for about a week. I am certain that the problem would return if I switch back to the old Thunderbird folder. I have no reason to do that other than for testing purposes to help track down the cause of this weird problem.