I have used Thunderbird for years (now on 128.5.2esr (64-bit) for Mac). I have a very large number of folders, and I would like to have a default setting for columns in new folders I create. I am aware that you can change the column setting in the folder by clicking the "Select columns to display" button and selecting the ones you want, and that you can change the setting for all folders in an account by going to the "Apply columns to..." > "Folder and its children..." > select the account > select the account name at the top of the list. But I would rather not have to do that every time I create a new folder, but I can't find any other way to do it anywhere, including on another answer to a question in this forum, https://support.mozilla.org/en-US/questions/1426413. Then I found two settings in the Config Editor... that seem like they might be where this can be done: * mailnews.database.global.views.conversation.columns, whose settings in my case are: {"selectCol":{"visible":false,"ordinal":"1"}, "threadCol":{"visible":true,"ordinal":"3"}, "flaggedCol":{"visible":true,"ordinal":"5"}, "attachmentCol":{"visible":false,"ordinal":"7"}, "subjectCol":{"visible":true,"ordinal":"15"}, "unreadButtonColHeader":{"visible":false,"ordinal":"9"}, "senderCol":{"visible":false,"ordinal":"17"}, "recipientCol":{"visible":false,"ordinal":"19"}, "correspondentCol":{"visible":true,"ordinal":"21"}, "junkStatusCol":{"visible":false,"ordinal":"11"}, "receivedCol":{"visible":false,"ordinal":"23"}, "dateCol":{"visible":true,"ordinal":"25"}, "statusCol":{"visible":false,"ordinal":"27"}, "sizeCol":{"visible":false,"ordinal":"29"}, "tagsCol":{"visible":false,"ordinal":"31"}, "accountCol":{"visible":false,"ordinal":"33"}, "priorityCol":{"visible":false,"ordinal":"35"}, "unreadCol":{"visible":false,"ordinal":"37"}, "totalCol":{"visible":false,"ordinal":"39"}, "locationCol":{"visible":true,"ordinal":"41"}, "idCol":{"visible":false,"ordinal":"43"}, "deleteCol":{"visible":false,"ordinal":"13"}, "xnoteCol":{"visible":false,"ordinal":"1"}} and * mailnews.database.global.views.global.columns, whose settings in my case are: {"selectCol":{"visible":false,"ordinal":0}, "threadCol":{"visible":true,"ordinal":0}, "flaggedCol":{"visible":true,"ordinal":0}, "attachmentCol":{"visible":false,"ordinal":0}, "subjectCol":{"visible":true,"ordinal":0}, "unreadButtonColHeader":{"visible":false,"ordinal":0}, "senderCol":{"visible":true,"ordinal":0}, "recipientCol":{"visible":true,"ordinal":0}, "correspondentCol":{"visible":false,"ordinal":0}, "junkStatusCol":{"visible":false,"ordinal":0}, "dateCol":{"visible":true,"ordinal":0}, "receivedCol":{"visible":false,"ordinal":0}, "statusCol":{"visible":false,"ordinal":0}, "sizeCol":{"visible":false,"ordinal":0}, "tagsCol":{"visible":false,"ordinal":0}, "accountCol":{"visible":false,"ordinal":0}, "priorityCol":{"visible":false,"ordinal":0}, "unreadCol":{"visible":false,"ordinal":0}, "totalCol":{"visible":false,"ordinal":0}, "locationCol":{"visible":true,"ordinal":0}, "idCol":{"visible":false,"ordinal":0}, "deleteCol":{"visible":false,"ordinal":0}} The first one matches the columns I see in a newly created folder better, having the "xnoteCol" entry, but my new folders also have several columns related to my CardBook extension at the bottom of the list. Moreover, the settings' arguments don't make sense in terms of what I see. For example, I see the Thread column, whose settings – ("threadCol":{"visible":true,"ordinal":"3"} – make sense since "visible" is set to "true", but I also see the Attachments column, whose settings – "attachmentCol":{"visible":false,"ordinal":"7"} – *don't* make sense because "visible" is set to "false". Similar no-sense settings occur in the second setting. So there *is* a way to change the default column settings in Config Editor..., which makes a whole lot of sense, but the way the settings are set in these two settings, which apparently are not the ones that fully determine my default settings given the CardBook-related columns that I see, do *not* seem to make sense. The "Folder and its children..." approach works, but it makes it harder than it should be, and it seems like there must be a way to change the defaults in Config Editor.... If there is, please tell me how. Thanks for any help you can give...