Various settings - case processing

[macben]

Hello everybody,
if I edit from a case and there click on answers, then the email mask appears where I can enter the answer.

There I can also choose whether the answer should be sent via the personal email address or the group mailbox.

I would like to set the following:
- Sender email address: always the group mailbox
- The field cc should always be empty, I do not want to receive a copy of the email.

Where can I set this accordingly?

Many Thanks!