first of all, Cai needs to confirm whether the sending company is the trademark owner of the goods sold by Cai, which can be confirmed by trademark inquiry of the Trademark Office. After confirming that the company is indeed the right holder, if the goods sold by Cai are indeed produced by the sending company and Cai obtains these goods through legal channels, then according to the exhaustion doctrine principle, as the owner of the goods, Cai has the right to decide to sell these goods again, which does not constitute infringement; However, if the goods sold by Cai are not produced by the sending company, but are produced by others imitating the genuine products of the sending company, according to the provisions of Article 52 of the Trademark Law, trademark infringement includes the act of selling and infringing the exclusive right to use a registered trademark. Therefore, Cai's behavior constitutes infringement. Article 57 of the Trademark Law of the People's Republic of China commits any of the following acts, all of which are infringement of the exclusive right to use a registered trademark: (1) using a trademark identical to its registered trademark on the same commodity without the permission of the trademark registrant; (2) Without the permission of the trademark registrant, using a trademark similar to its registered trademark on the same commodity, or using a trademark identical to or similar to its registered trademark on similar commodities is likely to lead to confusion; (3) selling goods that infringe upon the exclusive right to use a registered trademark; (4) Forging or unauthorized manufacturing of registered trademark marks of others or selling forged or unauthorized registered trademark marks; (five) without the consent of the trademark registrant, the registered trademark is changed and the goods with the changed trademark are put on the market again; (6) Deliberately providing convenience for the infringement of the exclusive right to use a trademark of others and helping others to commit the infringement of the exclusive right to use a trademark; (seven) causing other damage to the exclusive right to use a registered trademark of others.