Not so much a question, more of a "just in case others have similar problems" post... Searching here and elsewhere on reddit/stackoverflow/etc, there are a lot of posts around fixing IMAP "ghost folders" in Thunderbird. I've had this problem persistently for years, and decided to finally try and get to the bottom of it on one of my accounts. I filed https://bugzilla.mozilla.org/show_bug.cgi?id=1835023 and tried variations of different fixes, but the main clue that this was related not to Thunderbird, but the server, came when I saw the same ghost folders appear on a completely separate/fresh install of Thunderbird, after nuking every shred of Local/Roaming/etc profiles, on a completely separate machine that didn't have TB installed before. The ghost folders *had* to somehow be known to the server, as otherwise how would TB know about them? In the end, with much to-ing and fro-ing with my email host provider (who, bless them, did their own bit of research and sent me to various posts here where the various "solutions" are discussed - e.g. unchecking the "Show only subscribed folders" option, which really just hides the problem rather than fixing it), it turns out the core issue was indeed a borked subscriptions list on the server. > I located the folder mentioned in the subscriptions file that is generated by cPanel / Roundcube: /home/splinter/mail/splintered.co.uk/redux/subscriptions [ed: my account is redux@splintered.co.uk, so this will obviously vary depending on your specific server setup] > > I've re-created this and re-subscribed the folders via Roundcube - i'm no longer seeing the extra folders in the above file. This, getting the subscriptions to be regenerated on the server, is what in the end fixed this for good. All other tips (unchecking the subscribed folders option, or trying to create a new folder with the same name as the ghost folder, etc) seem to just effectively "plaster over" the fundamental problem. Your mileage may vary, but thought I'd post this here too, as I'd have loved to see this solution being noted here too, instead of sending me down various fruitless rabbitholes...