Whether the notification of passing the preliminary examination of the patent is stamped with the official seal?

No. Nowadays, most patent applications are submitted electronically through the system. After the Intellectual Property Office accepts the application, it issues an electronic acceptance notice, which is not stamped with the official seal. The company's official seal is the company's seal for handling internal and external affairs. The company's official letters, documents, and reports to the outside world use the official seal. Documents stamped with the official seal have legal effect.