Take context from the input text and decide on the accurate relationship between 'Australia Post' and 'mail' from the options provided.
Options: founded by, employer, industry, operator

The parcel, containing sew-on patches of the club's crest, is believed to have fallen behind machinery in a sorting centre at Australia Post -- the state-owned mail service -- only to be discovered recently when the company moved to another facility, reported Xinhua citing News Corp. Former committee member of the tennis club Irene Garrett, who the package was addressed to, said she "had a good laugh" when the item finally arrived.
industry