Referencing same question here: https://nation.marketo.com/message/15581#comment-15581
The "view as web page" comes across as the preheader in my text version - how can I get the preheader to show up correctly in the text version?
Please move the question to Products. "Community" is for questions about the Marketo Nation website itself, not the Marketo product. And yes, this is confusing.
The answer is to use {{system.viewAsWebpageLink}} in the body (and turn off the default option).