Thank you for answering me. 1.I mean to get rid of all of them in one clic. You see, I have more than 2000 unread, the rest are red flagged. Which means I have to delete 20-50 a time, many times.....2. Mac OS High Sierra 27inch, late 2009. 3.Apple mail. 4. yes external, but full now. 5. Yes permanently removed