However, it's definitely true that email is typically used both for "serious and well-argued discussions" and for chatty threads along the lines of

  Thanks.

  BTW How are we looking for this month's revenue target?
  
  >No idea, maybe the data load didn't run last night,
  >I'll look into it.
  >
  >>This report looks broken, the opportunity I closed
  >>yesterday isn't in there, what's up?