I don't think you should feel awkward. I refer to all my teachers in emails as professor ( unless I want to list more detailed honorifics ). My current analytic

I don't think you should feel awkward. I refer to all my teachers in emails as professor ( unless I want to list more detailed honorifics ). My current analytics guy is clearly very smart, seems to be in that adjunct zone, but I address him as professor out of sheer respect.