Audit Defense is included in the purchase of MAX benefits. So if you purchased MAX, that is why you received the email. You can log into your account and view your order details/fees to see the price of MAX. MAX is an optional add-on, so you would have had to add it in order to get the benefits. More info here What is MAX?
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I did not sign up for the max, so why am I getting this message and I'm having a hard time getting into myu account. the 6 digit codes are not working, I am wondering am I getting screwed