Wurdearring: 4 fan de 5 stjerren

I know about that. Right click Folder and click duplicate messages...; A window appeared and showed me all duplicate things, I followed the instruction, and click on duplicate list (left click) for message to display, but nothing happened ?? I use thunderbird 3.1.15

Dizze beoardieling giet oer in eardere ferzje fan de add-on (0.1.10).  Dizze brûker hat oare beoardielingen fan dizze add-on.

Did you click or double click the messages? Actually the state of an E-Mail should toggle between "KEEP" to "DEL" when you double click them.