Rated 5 out of 5 stars

by tbirduser99 on July 22, 2015 ·

In Thunderbird 38.1.0, Folder Pane Columns is a built-in feature.
If you run with the traditional menu bar (selections at the very top of the window), the option is View | Layout | Folder Pane Columns .
If you use the application menu (an icon of three horizontal lines near the upper right of the window), the option is Options | Layout | Folder Pane Columns .
In some localizations, it might be Preferences | Layout | Folder Pane Columns .
But note that under the application menu, the Layout option is *not* under View.

This user has a previous review of this add-on.