Answer
Yes, but it needs two things together: write the message content using HTML (for line breaks specifically, <br/> tags work well, e.g. between each line of a multi-line notification), and make sure the mail sender used for that event is configured with Content Type set to text/html in Setup IFS Connect. Without the sender's content type also being set to text/html, the HTML tags you write will just show up literally as text in the email instead of being rendered as formatting.