Z 5 z 5 hwěžkow pohódnoćeny

Very useful, many thanks!

It would be great if in addition to the button you could also use a keystroke, for example the letter "H" to activate the function.

Tute pohódnoćenje je za předchadnu wersiju přidatka (5.1). 

With the key combination Ctrl + Alt + F5 you call the function of the button (the function depends on the options). Simpler keyboard shortcuts are already used by Thunderbird itself.