Rated 5 out of 5 stars

For the people who want the count of unread messages to be in bold:
Click on the icon to the right of the Size column, and uncheck Unread in the dropdown list. Then Unread will not appear as a column, but the Unread count will appear in bold, in parentheses after the folder name.

This review is for a previous version of the add-on (0.4).