Do I have to send a thank-you letter from the Public Security Bureau to the Propaganda Department?

There is no need for the Public Security Bureau to send a thank-you letter to the Propaganda Department.

The public security bureau is an organ for maintaining social order and ensuring people's safety. Its duties include preventing, stopping and investigating illegal and criminal activities, maintaining social order and ensuring the safety of people's lives and property.

The propaganda department is responsible for propaganda work, and its duties include publicizing the party's line, principles and policies, the achievements of reform, opening up and socialist modernization, the achievements and experiences of public security work, and the advanced deeds of advanced figures.

Therefore, the thank-you letter does not have to be sent to the propaganda department, but to the relevant departments of the bureau, such as the office and the public security department.