Use Split Tunnelling to exclude TB from VPN monitoring:

https://support.norton.com/sp/en/us/home/current/solutions/v131881814

On Norton 360 / Privacy / Secure VPN / Open / Settings, there is no "slider to Enable VPN Split Tunneling," despite what is claimed on https://support.norton.com/sp/en/us/home/current/solutions/v131881814 (last modified 12/11/2024). Thanks, however, for your reply, sfhowes.

On Norton 360 / Privacy / Secure VPN / Open / Settings tab 'Enable VPN split tunneling' section On the right is a lozenge shape with pink background and it has a red circle with a white X in it. - See image below as guide. That is the slider - it moves left and right. You can left click and hold down to drag OR use a left click on red cicle to force a green circle. see image below as guide.

Then you need to click on the button which in my case says 'Edit Apps' and follow instructions to add Thunderbird to exclude it. Instructions at link mention 'Add' and 'Manage Apps', but mine says 'Edit Apps' then you click on 'Add Application'. Locate the directory where program is installed eg: C://Program Files/Mozilla Thunderbird and add the 'thunderbird.exe' and then add the 'updater.exe' program files. Finally click on 'Save'

I do not use VPN as I got fed up with correct links opening incorrect locations in my browser and other issues. But tunnelling is vital if you use VPN as many servers don't like atempts to access server when it looks like it could be a hacker from anywhere.

Thank you, Toad-Hall, for your response. The term "slider" is what confused me; however, that is what I had done before. I already tried your suggestion to exclude Thunderbird's thunderbird.exe and updater.exe programs. Unfortunately, even doing that, Thunderbird email software still requires me to turn off Norton VPN at times. Sometimes, however, Norton VPN remains on, and Thunderbird email still gets and sends emails. It's a strange little glitch that is yet to be resolved.

Have you considered asking Norton paid support folk how to configure their product? I think you should.

Yes, Matt, I thought about calling the usually helpful folks at Norton support, but I solved my own problem! Toad-Hall's previous comment got me to thinking. Yesterday, I added nine of the eleven ".exe" (executable) files -- in C:\Program Files\Mozilla Thunderbird -- to Norton 360 / Privacy / Secure VPN / Open / Settings / Enable VPN split tunneling / Excluded apps from VPN / Edit Apps. That solved the problem so far! Yesterday and today, so far, I can get and send emails in Thunderbird email software without needing to turn off VPN! Thanks for your suggestion.