I was checking out the classified and say someone was accepting USPS Money Orders and certainly if you know the person and trust them there is no problem. With that said I know for a fact that USPS Money Orders can be fraudulent. I worked in the financial industry before retirement and dealt with fraud against customers and against the company. Basically if it is printed it can be copied, I’ve seen 1 IRS check that was fraudulent. If you accept one once you know it has been cleared and is no longer negotiable make sure you shred it.