I was looking for the same thing, so I built it. It's a WordPress plugin that outputs a static copy of your site to a ZIP or a directory of your choice. The thought being that you put WordPress on a subdomain (e.g. wp.example.com) and have the main site (www.example.com) served by the static copy.
> That being said, it wouldn't hurt to start off with a simple sentence that reminds/reaffirms the value of their product to everyone.
I think most newsletters could benefit from this, particularly if they're going out ~once a month or less. patio11 does a good job of this with a quick two sentence introduction: (1) who is it and (2) why am I getting this.