Some advice: Think twice about invoking that option. Leaving email on the server can be a life saver if you ever accidentally delete an important message on your machine. I know that I have gone back to my ISP server (GMail) on many an occasion to retrieve mail that I lost or didn't mean to delete on my machine.
Shop for your Apple, Mac, iPhone and other computer products on Amazon.
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.