This isn't the sweet spot for email.
Consider switching tactics, and serve the file-change information via RSS (that's a little more work) or (depending on the need for longevity of the notifications) maybe via (networked) Growl.
A content-management system can generate these XML-based notifications, as can the (retiring) iWeb stuff.
Basically, this is something that detects and runs when the containing directory is modified (probably via a Folder Action), and that then either dynamically generates the RSS when the change is made, or that serves up the current data when the RSS query arrives.
This looks fairly close to what you'd want for creating an RSS feed.
And there are ways to generate XML in AppleScript.