Today I tested the Create Private Discussion feature in the Jive for Outlook plugin. I typed in the surname of a colleague in the To box, and it correctly found her profile and suggested her in a dropdown. However, there seemed to be no way of then selecting her using the keyboard. My suggestion would be that this should work in the same way as input fields for user names on the Wiki (Jive SBS web platform), e.g. on the Send as email page.