Is Yanwen express company is partner of China post? Will package arrive me if incorrect zip code?

I always put zip code : 855. But, all my packages shipped by China registered air mail, Swiss post, Singapore post... Etc. mostly reach me from 3-5weeks. All of package sent by YanWen express ( even some of China small package ) are no info even it shipped almost 2 months. When packages arrived Cambodia, where will Yanwen & China small package keep package at for shipping from China to Cambodia? Cambodia post, company or door to door service?