I use CC quite a lot. People in the CC are supposed to read the email because it is in their interest, even though they don’t need to reply.

E.g.

To: Graphic Designer Cc: Programmer, Middle Manager We considered the three options that you gave us. We decided to go with option 2 because option 1 was too technically complicated to implement and the big boss didn’t like the color of option 3. Please, send the assets to Programmer and forward your invoice to Middle Manager.