Correct Syntax for Generating HTML Email using AlternateView

I’m trying to use the AlternateView to cater for both HTML and Text clients. I would prefer to use HTML and only fall back to text where necessary. I started re-coding an old console app to do this but I still have carriage returns and newlines as “/r/n” in my code and my problem is trying to figure out how and where to use Environment.Newline instead of these?