Is it illegal to send a text message to the defendant in the name of legal aid saying that I will sue him?

Break the law. Violation of the provisions of civil procedure is an important part of the national legal protection mechanism, aiming at protecting the legitimate rights and interests of citizens, legal persons and other organizations. Either party should abide by the principles of honesty, credibility, legality and compliance, and send short messages to the defendant under the guise of legal aid, which will mislead the proceedings and affect the fair trial of the case.