I agree with Swampwalker if the money you need to send is more than $300 the $12 for express overnight mail is very much worth it for peace of mind. If less than $300 certified mail for around $2 is a good choice also.
Another tip for sending a money order via USPS is include a dark piece of paper and sandwich the money order on it so it's not obvious what's inside.
Another tip for sending a money order via USPS is include a dark piece of paper and sandwich the money order on it so it's not obvious what's inside.