A little while ago (November 2012 probably) I changed a mailing list from Hypermail to Mailman and wanted to keep some of the look-and-feel of the archives, e.g. background colour and fonts. So I patched mailman 2.1.9 in CentOS 5 to include a CSS stylesheet link in each generated HTML page, replacing e.g.
<BODY BGCOLOR="#ffffff"> with just <body> and adding e.g. body {background-color: #ffffff ; color: black; } in /pipermail/mailman.css, so that HTML style such as FONT and SIZE is removed from the Python code. (I only have one list on that server and didn't implement per-list style) I also changed a few things e.g. content-type to get zero warnings and errors from the W3C online validator.
Now if I want to get DMARC functionality I'll have to jump past the RedHat/CentOS release and build 2.1.18, and re-patch for CSS.
I was wondering if there was any interest in incorporating CSS into the official releases.
-- Andrew Daviel, TRIUMF, Canada Tel. +1 (604) 222-7376 (Pacific Time)