I have been renting a house for 2 years in Oakland, CA. As of 7/10, my July check was not received by my landlord, who lives in New Jersey. I mailed it 6/28, allowing 4 days to get there. She now wants me to pay a $170 penalty. Can I hold the USPS liable for not delivering the mail in a timely manner and didn't I do my part by mailing the check on time? This never happened before.