Went through this several years ago, and yes you can but YMMV... unfortunately I can't find my notes and it isn't very straight forward, tech support helped me do it once. You have to edit the template file, which is in some weird code and not where you expect if I recall. And it doesn't backup or survive an upgrade. Customer realized "awhile" after an upgrade (like a year after) that the emails were not the same and when I called support then they couldn't help me.