Rated 4 out of 5 stars

Really miss this excellent addon. Still not working in Thunderbird 68.3.1. There is no uption to Mark All Read either on the toolbar or in the drop down menu. Hope that it is fixed soon.

Rated 5 out of 5 stars

This very useful addon does work in Thunderbird 60.3.3.
Customise and drag the button to the Mail Toolbar. It will work on individual folders, Great addon.

This review is for a previous version of the add-on (0.7.2).