Hi there Holden_Dylan,
Welcome to Apple Support Communities. We understand you'd like to block certain spam emails from coming through, but specific to an address they include in the CC field. There isn't a way to do this specifically on an iPhone. If you get email on a Mac, you can set up rules within Mail to manage those particular messages.
Use rules to manage emails you receive in Mail on Mac - Apple Support
As for your iPhone Mail, it will also depend on who your email provider is that is receiving this junk email. If it's iCloud, the best steps for reporting junk email like this are the steps in our article here:
Report and block spam in iCloud mail - Apple Support
If it's another email provider, there are usually steps they have within their mail settings to report or block emails like that.
Best regards.