Z 4 z 5 gwězdkow pógódnośony

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

Toś to pógódnośenje jo za pjerwjejšnu wersiju dodanka (0.1.10).  Tós ten wužywaŕ ma druge pógódnośenja toś togo dodanka.

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.