How Does One Make Genius Bar Appointment?

I apparently have 370 gb of emails that Apple can't find or delete. They are taking up most of my hard drive. After failing to solve my problem, Apple phone techs say they will call me back, but do not. I would like to make an appointment at the Genius Bar in my closest store to see if they can help. However, the Apple website just routs me to a page that tells me to delete my email account, then reenter it. Can someone tell me how to make a store appointment? When did all things Apple go to ****?