Dealer reg confirmation fix

Somehow the last PR was missing the bit of code that actually sends emails.

This PR also includes suggested text changes
I don't think it's necessary to fix before noon.  The ``MarketplaceEmail`` code checks whether an email was already sent and doesn't care how it was sent, so it won't matter if we make this transition later; no one is going to get a second email when we make the change.  I can do it tonight after work.