You can send yellow horror messages.

You can't. According to the Law on Public Security Administration Punishment, the contents of short messages containing obscene, gambling, fraud and terrorist information are severely cracked down and cannot be sent to others. Whoever repeatedly sends obscene, insulting, threatening or other information and interferes with the normal life of others shall be detained for not more than five days or fined not more than 500 yuan. If the circumstances are serious, they shall be detained for not less than five days but not more than ten days, and may also be fined not more than 500 yuan.