Ok I can confirm that the issue is directly related to the fact that the TO: needs to be whatever the account used for help desk is.
TEST 1: Result = SUCCESSFUL
- sent to support@company.au
- sent email from @hotmail.com account
- CC'd in @gmail.com account
TEST 2: Result = FAILED
So for the email collaboration feature to work you MUST have everything the same > Helpdesk email = TO: email on anything sent by client/customer.
I see this as a bug. If business name changes or domain changes and people set up a forwarding rule or alias then the parsed email shouldn't remove the CC'd users even if the TO: field is different.
Thoughts @KevinTheJedi ??