I'm using dovecot-2.3.17.1-1.fc34.x86_64 on fedora34 and Thunderbird 91 on fedora35. When creating a folder of type "folders only" in Thunderbird, then trying to delete it, it doesn't actually delete it from the filesystem. Is this a permissions problem? Or perhaps a Thunderbird problem?

Are you using MBOX backend?

I think I ran across this problem and it's some confusion as to whether the target is a file or directory. I was finally able to delete it by appending '/' to the name of the folder in my mail reader, but some mail readers do not allow you to type the mailbox name to delete. I believe Tbunderbird has some IMAP server setting that will give it a hint.

Joseph Tam <jtam.home@gmail.com>