I have two people, Frodo and Gandalf.
I have a list with the person/group site column "Assigned To"
I have a view "View1" that only shows items where Assigned To is empty
I have another view "View2" that only shows items where Assigned To is not empty
I've configured alerts on this list so that Frodo gets an alert when anything happens to items in View1, and Gandalf gets an alert when anything happens to items in View2.
They both receive emails when they are supposed to, however, Frodo gets an additional email at the same time as Gandalf when the list item is transferred from View1 to View2 by changing that field.
Why is this happening? Does it have something to do with OnUpdating and OnUpdated event receivers? I've tried changing the alerts to be when "existing items are modified" instead of "All changes" but it doesn't seem to make any difference.