Delivery service by South Korea's postal service operator Korea Post ranked No. 1 in consumer satisfaction, a survey showed Friday.Korea Post received 3.97 points out of a possible 5 in overall satisfaction scores on a survey conducted by the Korea Consumer Agency.It is followed by CJ Korea Express Corp., South Korea's largest logistics company, with 3.86 and Logen, a logistics company, with 3.83. Lotte Global Logistics Co. and the logistics unit of Hanjin Group came in third and fourth with 3.