After clicking “Email” in the dropdown menu as shown above, click on the email you want to use. Click “Edit email” once you open the email if you’re not already taken to the direct email editing screen.
When in that email right click “View Page Source”.
After clicking that you will see a page with a bunch of code. Copy all of it.
Paste the copied code into Notepad--if you have a Windows computer--or download Notepad++ if you have a Mac computer and paste the code into Notepad++.
Finally, after putting that code into Notepad/Notepad++ save the text as a .html file.