I found an answer in a 2009 post. It's not as easy as if CC would create a button to copy, but it's better than re-creating from scratch. Go to the campaign you want to copy "FROM". Must make a copy - this does not work from Preview. Click to Edit it and you will see a box called HTML. Click HTML and copy the HTML code by highlighting it and using your keyboard to Copy. Go to the newsletter you wish to copy it "TO" and select the same - HTML box. Then overwrite the current contents with the data you copied (just delete what is there and paste what you copied). Select update and close. The new block should look exactly as the old block does. Links work too. Hope that helps.
... View more