I'm with the rest of you. I use Amazon workmail for my personal (and my family's) accounts, through my own domain and the web-interface disables anything but plain-text by default. Makes it easier to weed out shit I'm not interested in, if the message looks garbled with loads of tags visible it generally gets junked.
I've also set up my Outlook client for work to send/receive in plain-text only, despite occasionally getting stick from the boss for not slapping the massive "branding" images and various bullshit social media links in my signature. I just point out that HTML e-mails are a security risk and I count disabling that shit under the category of "being a good neighbour".