What can I send to the other party to make him afraid to send spam messages?

Harassment calls are basically made through network ports.

So he can't see anything you reply to.

Only interception can effectively stop harassing text messages.

Tencent mobile phone housekeeper is like a good one.

After successfully entering Tencent's mobile phone housekeeper,

Click Security Protection, Harassment Interception, Interception and Add Blacklist in the upper right corner.

Intercept hidden number phone function

Start the switch in the interception settings, and you can automatically intercept incoming calls with hidden numbers.

Effectively put an end to malicious phone harassment, and you can also set up intelligent interception.

The function is humanized and the operation is relatively simple.

There are many functions in it. You need your mobile phone. You can have a look.

I hope my answer can help you.