Outlook for Mac Version 15.10.0 doesn’t show people who else was CC’d into email

Hi,

I'm using Outlook for Mac Version 15.10.0, when I compose an emails and either CC or add email addresses To when the email is sent the recipients don't see that anyone else was CC'd into the email almost as if I have BCC people into the email. I have also tried adding people to the To field but with the same result.

Is this a known bug in Outlook for Mac Version 15.10.0?

Thanks,

Darren