[twobitshifter]

For security plain text is best. US Federal Government Recommendation is to disable html:

“Organizations should ensure that they have disabled HTML from being used in emails, as well as disabling links. Everything should be forced to plain text. This will reduce the likelihood of potentially dangerous scripts or links being sent in the body of the email, and also will reduce the likelihood of a user just clicking something without thinking about it. With plain text, the user would have to go through the process of either typing in the link or copying and pasting. This additional step will allow the user an extra opportunity for thought and analysis before clicking on the link.”

https://theconversation.com/the-only-safe-email-is-text-only...

That said theres another post on the front page about an Apple mail zero click exploit involving attachments so even plain text can’t dodge everything.