If you've downloaded a Marketo email's HTML using the built-in 'Download HTML' menu option before, it's likely that you got frustrated at the fact that the email still contains Marketo tokens!
Here's a nifty bookmark for your Chrome browser (I've only tested it in chrome), to download the HTML from the preview email UI.
2026 update:
Fixed a long time bug where the downloaded HTML is bloated with editor <div> tags after switching from the editing to previewing screen. Also automatically strips <script> tags - some time ago, when Adobe migrated interfaces, they started embeddeding New Relic scripts that measure app/page performance to the previewed email. Why inside the previewed email? ¯\_(ツ)_/¯ who knows?
javascript:(function()%7Bif(window.location.hostname.indexOf(%27marketodesigner.com%27)%20%3D%3D%20-1)%20return%20alert(%27Please%20preview%20a%20Marketo%20email%20to%20download%20HTML%27)%3Bconst%20a%20%3D%20document.getElementsByTagName(%27iframe%27)%5B0%5D.contentDocument.getElementsByTagName(%27html%27)%5B0%5D.outerHTML%2Cb%20%3D%20new%20DOMParser()%2Cc%20%3D%20b.parseFromString(a%2C%20%27text%2Fhtml%27)%2Cd%20%3D%20c.querySelectorAll(%27script%2Cbody%20%3E%20div%27)%3Bd.forEach(el%20%3D%3E%20el.remove())%3Bconst%20e%20%3D%20c.documentElement.outerHTML%3Bvar%20l%20%3D%20document.createElement(%27a%27)%2Ct%20%3D%20new%20Date()%2Ct%20%3D%20t.toISOString().split(%22T%22)%5B0%5D%20%2B%20%22_%22%20%2B%20document.querySelector(%22title%22).textContent%3Bl.download%20%3D%20t.replace(%2F%5B%5EA-Za-z0-9%5D%2Fg%2C%20%27_%27)%20%2B%20%22.html%22%3Bl.href%20%3D%20%22data%3Atext%2Fplain%2C%22%20%2B%20encodeURIComponent(e)%3Bl.click()%3B%7D).call(this)%3B%3Bvoid(0)%3B
Instructions: just add a new bookmark and copy & paste the whole chunk above into the URL then click the bookmark button when previewing a Marketo email (in marketodesigner.com)
Check out the similar bookmark for the new email designer here