Disable Evolution notifications on Gnome Panel (2)

In the end, I found the option, it is not under 'Preferences', but on the 'Plugins' one.
It is the 'Mail Notification' one (see screenshot).
The strange thing, it simply disables the gconf-editor keys I mention (and tested) on my previous post... Maybe I have tested it incorrectly...

Anyway, it is working, also, the same plugin allows you to customize the sound Evolution should produce (by default) when a new emails arrives.