Verification emails are HTML-only

Is your feature request related to a problem? Please describe.

To take a survey, I had to provide my email address and navigate to the actual survey contents using a link sent there. However, this email message lacked the more accessible, readable and versatile text/plain MIME part.

Describe the solution you'd like

All email messages sent to users should contain a well-formated plain text equivalent of their text/html part. Ideally, they would respect the various norms and conventions of plain text email like URL markup, text wrapping | format=flowed, etc.

Additional context

edit Here is a neat overview of a few of those "norms and conventions". /edit