I installed your newsletter archive extension, activated it and added the shortcode. As you can see it makes a nice list of newsletters:
When I click on one it says “e-mail not found”.
The link to the latest e-mail created by the shortcode looks like this:
Except, the previous newsletters can actually be seen here:
P.S. It would be great to do add limit and delay arguments. For example “display=5” would show only the last five. And “delay=1month” (day or year) would show the last five with the most recent one begin from a month (day or year) ago. You know, to give people a reason to subscribe – and not come to just the archive page to see newsletter offers written only for subscribers. : )