Preview pane
Is there anyway to turn off the preview pane in Thunderbird permanently so it doesn't come up when starting TB?. I am aware and use the F8 or drag down the splitter line but I don't want it to show at all like in other email programs
Alla svar (1)
TB should start with the same layout that was present at last closing. Help/Troubleshooting, Profile Folder, Open Folder, close TB, delete or rename session.json. Open and close TB a few times and see if the Message Pane status is maintained.
If you have CCleaner or equivalent app, it can interfere with TB settings.