How can I set up a way to stop email from downloading until I approve the sender


IMAP Tools
Well, if Earthlink is your provider you can use their "Suspect Email Blocking" feature.

Suspect Email Blocking checks to see if an incoming message is from someone in your EarthLink Address Book (an allowed sender). If so, the message passes to your Inbox. If not, the message is rerouted to your Suspect Email folder, while spamBlocker sends an automatic reply message, which lets the sender submit an allowed sender request.