I have seen on a couple of different task lists that the email sent out for notification of a task assignment gets sent to people who were never assigned to a task.
The email sent out contains a list of people crossed out (line through their name). It seems like the task is edited and previous old recipients are crossed out and the correct recipients added but the task may have just been newly created and all the people (those crossed out and those added) receive the email - even though those crossed may not be members/visitors/owners (i.e. zero permissions) on the site.
Any ideas why this would be occurring?