Thank you for your response. I was able to get it to work but in the most unintuitive way possible…
When I followed your instructions, I found the ability to apply rules, but it still did not work. So then I created a new rule with the one message selected, and in the email address field that I am targeting it rewrote it for me.
Instead of "newsletters@e.xyz.com"
It created the address.
"newsletters_at_e_xyz_com_s4s5d23aty5fb8_baz74009@icloud.com"
this is not something I could ever dream up myself, but I'm curious if it has something to do with this sender being sent to a "hidden email".
That's kind of weird and a little little bit disconcerting.