[MlMt] How to disable HTML parts altogether?

[Sam Hathaway]

On 21 Sep 2016, at 2:51 PM CDT, Sam Hathaway wrote:

> I don’t like sending HTML emails. What combination of knobs and 
> switches will turn HTML off altogether, even when I’m forwarding or 
> replying to an HTML-formatted message?

Sorry, forgot to mention, my environment is:
- MailMate 1.9.5 (5263)
- macOS 10.11.6 (15G1004)
- MacBook Pro (Retina, Mid 2012)