Thank you for the additional information. I am sorry to hear of your dilemma. I realize how frustrating this is for you, but I believe I have information which you will find helpful.
If he is threatening your safety
or your property then you can report it to the police and it is criminal harassment and can be prosecuted. Likewise, if he is making defamatory statements about you he can be sued for defamation and made to pay damages to you.
If the purpose of his communication is solely to annoy and harass you may be able to seek a restraining order against him. That will prevent him from further contact and subject him to sanctions for violation. A restraining order is somewhat complex in terms of the process and you would probably want to retain local counsel for that.
However, if none of those are applicable to his behavior then your options, from a legal standpoint, are somewhat limited. You can not really stop him from contacting other people. As for yourselves, you can block his texts and emails in your text and email applications. You will never even know they were sent. They will go straight to deletion.
It is my privilege to assist you. Let me know if you need further information. I hope I have helped you beyond your expectations in the service I have provided to you. I am here for you.
Since this forum is no substitute for your own legal counsel, you may want to verify the information I have provided with a local attorney who is familiar with your local laws and procedures.
I am happy to answer your follow-up questions and assist you until I am able to explain the answer to your satisfaction.