Hi Chris -
Essentially, the 3 step process is:
Click "New Message"
Post A Campaign Link or Picture to the body of the message (be sure to tell people what to focus on)
Click "Post" button
However, if you are looking for an in product post button or easy flow, we're not there yet... hoping we can get there!
How can you share the whole newsletter id you don't archive. I used screen shot but it doesn't include the entire newsletter just the screen showing?