As far as I can see, there are three different places where one can enable and configure notification settings in the dude. Right now I am a little confused if these settings interact, override or summarize each other. These are the places where I found the settings:
Settings button on the top menu => Polling tab
double click some device => Polling tab
double click some device => Services tab => double click some service => Notifications tab
if (* double click some device => Services tab => double click some service => Notifications tab is specified) service settings will be used,
else
if (* double click some device => Polling tab is specified) device settings will be used,
else
if (* Settings button on the Map settings menu => Polling tab is specified) map settings will be used,
else global server settings will be used.
endif
endif
endif
endif
It mean that service settigs has preference on device settings, device settings has prefference on map settings and map settings has prefference on global server settings.