This thread doesn't encourage one to use AWDs one is ineligible for, but it's a good resource if one chooses to do so.

To answer your previous question, the email is used mostly to cross-reference eligible addresses. You aren't likely to be required to confirm anything but it's on you if you are asked to do so.

Example: Allstate employees should be using emails such as [email protected], which would match with an approved domain list and satisfy the 'private' AWD requirement. But, if an agent uses [email protected] for some reason, they wouldn't be eligible for the rate despite being an employee. It's a bad way to check eligibility and not foolproof.