Please clarify what you mean by 'local folders'.

In Thunderbird 'Local Folders' is specifically a default mail account which does not connect to any server. Any folders within the 'Local Folders' mail account that contain emails, will be stored on your computer.

Pop accounts do not synchronise with any folders on the server. They just get access to server Inbox to download emails. This means all emails in all pop account folders are stored as independent copies on the computer

Imap accounts synchronise all folders with server, so these folders cannot be considered as independent copies. Whatever is on server is shown in Thunderbird imap account.

Post image showing problem.

I use local folders as a filing system for emails but wanted to delete unused ones and only succeeded in reproducing more.

Looks to me like you have dragged the folder into a lower location in the folder tree rather than deleted them.

why is it not responding I wonder. Are you using a flatpak and have no access to read write in the location the profile is located perhaps.

Hi Matt No, if I go to the folder and right click on it, a panel with "Delete" as one the options comes up and I click that. Thunderbird then freezes and I have to close it, but it reproduces more folders when I re-open it.

What happens if you use your keyboard to do the deleting? Have you checked the profile folder to ensure you have read write and allocate privileges for the profile files?

Matt Using the keyboard gives the same result. I'm sorry but I don't know where to find the profile folder. As all the copied folders show emails, if I delete the emails in one of the copies will this delete them for all folders?

I use local folders as a filing system for emails but wanted to delete unused ones and only succeeded in reproducing more.

That image shows the 'Local Folders' mail acount has an 'Archives' folder and all other folders are in the 'Archives' folder. It does not show anything in the Trash.

Move the folders you want to delete out of the 'Archives' folder so they become top level folders in the 'Local Folders' mail account - in other words drag folder so you are hovering over the actual 'Local Folders' account name and then release and folder should end up in 'Local Folders' as a top level folder thus getting it out of 'Archives'.

Then try deleting the folder you moved out of 'Archives'.

Thanks for your help!