What do you think we should do here? The only portable, sensible default I can see would be to use sendmail, but the pyramid_mailer API separates them into `mailer.send_sendmail` and `mailer.send`.

We would have to override the views in horus, but we may already be doing that, and we have open issues for the registration stuff anyway.

Not a blocker to merge this, but just wanted to write my thoughts.