CC is Not Working

When I’m logged in as root to the RT interface and I create a ticket, I
enter an email in the CC address and the message goes also to that address.
If I’m logged in as another user and I create a ticket, I enter an email in
the CC address, the message does NOT goes to that address. I checked the
maillog and the email address on the CC doesn’t even show in the maillog.

Any Inputs?