Here are the DMCA laws, read them.
https://www.copyright.gov/legislation/dmca.pdf
https://www.copyrighted.com/blog/dmca-guide
It's designed for copyright holders to protect their work. It's not for models, webmasters or even sites unless the creator of the material signs over copyright. In many cases, they do not or don't specifically sign it over.
It's a law that only applies if the server is in the US.
If the DMCA is ignored the next step in law is to sue the person infringing the copyright and the Host.
In reality, the Host will help you but only if you can prove you are or you're working on behalf of the copyright holder.
A DMCA needs to list actuals URLs where the infringing material is hosted.
Because the danger of sending out something like this is the sender, model, the webmaster can be countered sued.