Hello,
If you only want reachable events you need to create a collection that only shows these events. Do you know how to create these filters? When you created this filter you need to create and Automatic Event Handling task. This can be found under Options> Events>Automatic Event Handling>New task. Click new, type a name for your rule, next, now you select the filter you created earlier that only contains the unreachable events. Now push the next button, select all Systems or if you want a collection of servers that you want unreachable events from and click the next. In the next screen select the Send e-mail box.
I always also select the clear event so i know the event was emailed. IN the Email fields you type the email address you want to send to., next. This screen shows time filters if you don't want emails in the night or in the weekend.. Now the last next and if not already configured you can click the Edit e-mail settings to configure your email server..