When I send an email using “Send Email” action, I no longer see any formatting applied. Specifically line breaks but there was previously some basic formatting like a border around the div that the body of the email was in.
I use a template column to generate the body of the email (which has worked fine in the past).
I use Make for all my email needs, and I always use basic HTML tags to apply formatting. I’ve not tested, but I’d imagine that should work equally well with the Send Email action.