Password Protected Local Folders:
I wish Thunderbird had a way to password protect and encrypt some local folders and subfolders.
When you create a local folder, you would have the option to password protect/encrypt it (and its subfolders). Most emails don't need that kind of protection, or the slight hassle of entering the password, but sometimes there are emails (or email categories) that need protection. You would only need to enter the password when you open that folder. When you send or receive a sensitive email, you could put it in that folder/subfolder, and you are prompted to enter the password. Once unlocked, it behaves like all the other folders.
Please consider this idea! Thank you!