Review for Mark All Read Button by Firefox user 13135c
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.
This user has a previous review of this add-on.To create your own collections, you must have a Mozilla Add-ons account.