Is it illegal to send spam messages to others?

Sending spam messages without consent is illegal. Without the user's consent or request, or the user's explicit refusal, no organization or individual may send commercial short messages or make commercial phone calls to users. If the user does not explicitly agree, it shall be regarded as refusal. If the user explicitly refuses to receive after agreeing, it shall stop.

Legal objectivity:

Article 165 of the Civil Code of People's Republic of China (PRC) * * * The principle of fault liability. If the actor infringes upon the civil rights and interests of others through fault and causes damage, he shall bear the tort liability. If the actor is presumed to be at fault according to the law and cannot prove that he is not at fault, he shall bear tort liability.