Do you mean CC field in the external email you have received? I have got an email on v. 8.3 where CC field did not work in the SERP and the CC adressee haven't received a copy of the email.
I would like to know what BackgroundHALShouldPause does, and how to use it. While it's listed in the HAL Primitives report, it is not used in source code and it doesn't appear in the LMS HAL...