We have an issue where one user is mistakenly receiving appointment invites directed to another user.
Example, Joe B sends an appointment invite to Sally G, however Nora E gets the invite as well.
Nora E does not have any rights to Sally G's mailbox or calender, so when she tries to respond, she gets a "you do not have sufficient priviledges blah blah"
There are no forwards setup in their AD profiles. This only seems to affect the afflicted user (Nora E). It does not matter what user sends the invite (Joe B or anyone else in the organization).