5 つ星中 5つの評価を受けています

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.

これは以前のバージョン (5.1) についてのレビューです。 

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.