The global change notification doesn't seem to be called when an email is added to an existing item - it also seems that the notification is not sent for new emails create this way either. I also noted that they is no item in the history for an email being added
Are the "alerts" different?
I was also hoping for a way to only be notified in this specific case, not for any change.
Also under alerts it seems that most fields can be used to check for changes, but there is no option for emails being attached. Since I know of no way to change the value of any fields when an email is attached I don't know how to get an alert.
So currently I actually have no way of being notified of items begin created or modeifed by emails at all.
You guys seem to get notifications - so either I don't understand your explanation, or there is a bug.