Dada Mail v8 Quick Install Guide:
Importing Addresses into Dada Mail:
Magic User Templates
This screencast shows how to change the layout of Dada Mail to match your own website - it using HTML::Tree under the hood, which I wrote about, recently.
Dada Mail Scheduled Mailings:
This screencast showcases a few mature features in Dada Mail, including Sending a Webpage (whole or in part), as well as setting up a recurring scheduled mass mailing, that only sends when the source content has changed. Neat stuff.
Give Dada Mail a spin, if you haven't already - it's a long running, and fairly popular Perl web app. I would say one of the most popular Perl-based web app targeted for regular folks (as opposed to Perl hackers)