Email Notification: Server Errors: Only one email received in one full day (and clearly not onely one exception generated ;-) )

I turned on the email notification for errors (std level not paranoia) during the config wizard. It looks liek working as I received one of the them (cf screenshot). My only concern is that I only received one single error along my full day of testing. And clearly speaking I generated far more exceptions than only one single one.

So where are the other exceptions gone? What corresponds to the "standard" level? Is Jackrabbit excpetions also caught? etc... Not very transaprant for the webmaster. Perhaps some elvel of explanation (tooltip) in the config wizard could help clarify which errors are sent back to the webmaster.