Since my 2014 MacBook Air seems to work reasonably well I have not updated the OS from High Sierra and now I see that OS updates are unavailable on such an old computer. There are some things I'd like to do that are ridiculously slow. One is to delete e mails from my Inbox. I can't seem to highlight and erase a group of e mails. Have to do one at a time which is tedious to say the least. Any suggestions? thanks.