I think a lot of them use tools like Ahrefs and Semrush to scan the "authority" of a website. The bigger the number (these tools go to 100) the higher the likel

I think a lot of them use tools like Ahrefs and Semrush to scan the "authority" of a website. The bigger the number (these tools go to 100) the higher the likelihood that you'll get pestered with these emails. For one of my domains, the one I was talking about, my rating is 70 and I have very good incoming links from various reputable sites. I'm an "easy" target in that regard.