I would have mailed the check too, but as far as filing before 11-30 I wouldn't count on anything getting processed. I sent them a response to a CP notice last week by certified mail with return receipt and have been checking on it through USPS tracking, It became "AVAILABLE FOR PICKUP" at the Cincinnati post office a week ago (on Nov. 4th) and as of this minute it's still laying there. I've never had one wait that long, so I assume they're pretty far behind.