Actually, when you responded with, "You are correct. You cannot mark all emails for deletion at one time. There is a checkbox that based on appearance and convention should cause all to be selected. But it does nothing. Either a bug or something put in with plans to add code to select or deselect all.", you gave me exactly what I was hoping for, the answer to my question.
Can you return the favor and tell me what the answer was. Because my answer does not work for me.