Hello,
I am currently exploring and really enjoying the new Thunderbird Supernova and I like the new unified folders feature. However, there's one thing keeping me from using it. My email provider divides emails into INBOX and newsletters folders. However, Thunderbird doesn't recognize the newsletters folder as a regular folder for incoming messages and doesn't include it into the unified folders view.
It would be helpful if Thunderbird knew what the newsletters folder is for and would include it into the unified folders view.