What I'd like to see is a way to turn on plaintext email replies only for certain recipients. I know you can't do that in Outlook it's a global setting or nothing - can any other (non-cloud) email client do it?
This is what I do at work. My work uses Outlook which does not support format=flowed [2], meaning my plaintext emails would look weird to colleagues who use the standard Outlook settings. Outlook will also default to responding in plaintext to a plaintext email. To avoid forcing my preferences on my colleagues, I now use an automatic filter [3] to convert my plaintext emails into HTML using a Markdown parser. My email client then sends both parts: the HTML and plaintext part as a multipart/alternative email.
[1]: http://www.mutt.org/doc/manual/#send-hook
[2]: https://joeclark.org/ffaq.html
[3]: http://www.mutt.org/doc/manual/#send-multipart-alternative-f...
Next question.... overriding reply-on-top for mailing list replies? :)
Is this sarcasm? Because I know folks that consider anything but plain text emails to be rude.