Thunderbird 3: show total number of items in folder?
In TB38, this is again standard functionality but hidden in :View => Layout => Folder Pane Columns.
For Thunderbird 3, it appears that you need an extension, see the mozillaZine article, Expanded columns in folders pane:
- Install the Extra Folder Columns add-on. This will add a small square control at the right end of the column headers in the folder pane. You may need to disable version checking or edit the version it supports to install it.
- Click on that control and select Unread, Total, and/or Size.