Auto-complete list control

Per Customer Request:

When sending an email, I think it would be a good idea to allow us to turn off auto-population or to prevent auto-population from happening unless we manually choose to "add" that person. I've tried looking in my settings, and contact information and didn't see any option for this, so I called today. I was advised today by tech support that I can add in a couple letters into the "to" section of my email to see a list of addresses that I can then "X" off to remove, or to keep. However, having customers choose if they want an address added and/or turning off auto-population can give us more control over our email list.