Thunderbird Memory Usage

You do have an issue. But there are some quick steps you can try before going all in. I have included them below the image. Just for some comparison, I have Thunderbird on windows 11 with Windows defender for an antivirus. My 30+ Gb profile on the ESR version uses less than 1.5Gb and the daily build with a small testing profile and a couple of accounts uses less than .5 just happened to have chrome with 4 tabs and Firefox with dozens open when I made the screen shot. <img src=https://assets-prod.sumo.prod.webservices.mozgcp.net/media/uploads/images/2026-06-25-20-54-54-5574a3.png> To diagnose problems with Thunderbird, try one of the following: *Restart Thunderbird with add-ons disabled (Thunderbird troubleshooting Mode). On the Help menu, click on "Troubleshooting mode". If Thunderbird works like normal, there is an Add-on or Theme interfering with normal operations. You will need to re-enable add-ons one at a time until you locate the offender. *Restart the operating system in '''[http://en.wikipedia.org/wiki/Safe_mode safe mode with Networking]'''. This loads only the very basics needed to start your computer while enabling an Internet connection. Click on your operating system for instructions on how to start in safe mode: [https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode Windows 10], [http://windows.microsoft.com/en-us/windows-8/windows-startup-settings-safe-mode Windows 8], [http://windows.microsoft.com/en-us/windows/start-computer-safe-mode#start-computer-safe-mode=windows-7 Windows 7], [http://windows.microsoft.com/en-us/windows/start-computer-safe-mode#start-computer-safe-mode=windows-vista Windows Vista], [http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/boot_failsafe.mspx?mfr=true" Windows XP], [http://support.apple.com/kb/ht1564 OSX] ; If safe mode for the operating system fixes the issue, there's other software in your computer that's causing problems. Possibilities include but not limited to: AV scanning, virus/malware, background downloads such as program updates.