Can you tell me more about this? you can create folders in Thunderbird that are Thunderbird folders only and once created, you treat them as archive folders in Thunderbird? and as a folder in Thunderbird, it means that Thunderbird knows about it, but your PC does not overtly know about it (only knows about it by virtue of the fact your PC knows what Thunderbird has in it, i.e., perhaps the folder is in AppData somewhere)? and your provider e-mail does not know about it (after you delete it there)? Trying to get a handle on this.