I've recently had to abandon my POP account and subsequently my ISP, who has stopped supporting email clients other than their own. I wanted to keep using Thunderbird and while I accept POP is gone, I wanted to maintain access to my old, downloaded emails as they form a useful database of information. I've done this by disabling the server connections of the old POP accounts but leaving accounts themselves in Thunderbird and adding my new web-based account (Protonmail) to download current emails into Thunderbird. All this has been accomplished successfully and works well. It did take a wee bit of work to get all this 'successful and working well' and during the process Thunderbird has somehow managed to duplicate several folders that can not be deleted. They are all empty except for the ones with the > beside them and those contain the expected material that should be there (so are the ones I want to keep.) Any way of getting rid of all these duplications, especially in Local Folders? They don't seem to be hurting anything but I find them annoying. I'm on a Mac desktop with Ventura 13.3.1