I'm going g to assume your family is like my family. My family's attempts to find me & track me down are a display. It allows them to showcase how caring they are and what a perfect family they are. They use it to gaslight & manipulate without ever taking accountability for what they've done. In their minds, they've done nothing wrong and all this tracking down allows then to advertise that.

You could try sending them an email. But keep it short and to the point. Basically just that you ch8se to go NC and ask then to stop trying to contact you. I'd also send it to as many people as possible using the BCC line.

I would close down the email address you use so you aren't tempted to read their responses & get pulled back in. Proton mail is great for this (it's free & very secure). Otherwise you are giving them a communication channel. Most of what they send will abusive in some way. You don't need to enable exposing yourself to that.

I am sorry you are going through this. It can be so hard to get those abusers & enablers to stay out of our lives. But as you said, they never respected our boundaries so why would they start now?