After several attempts and official communication with "Servicio Postal Mexicano - Correos de Mexico", personnel simply denies any information. After chatting with various mexicans, is awfully well-known than post in mexico steals any parcel they wish, with the only exception of high-cost services (EMS, etc). Even showing the printed sheets (CAINIAO, TrackingMore, etc.) post employees only declares the involved Tracking Numbers as "untraceable" because "those are not valid numbers" for mexican mail system.