I recently re-installed Win 10 and Firefox and Thunderbird. For the first several months Thunderbird acted like it is supposed to.
I could highligt [chose] an e-mail and get options to archive; delte; mark as junk etc. Without opening the e-mail.
Now it has started automatically opening the e-mail in it's preview pane. You now have to [click] open the e-mail to be able to get the delete option to show up at all. To me a dangereous thing. Now I have not changed any settings at all. Even the structure of the page has changed a little.
Since I did not take a screen shot when it was working correctly I have nothing to compare it too now.
As far as turning the preview pane on or off I find no such option in my settings at all.
Thank you for any ideas on this matter.