To send users a daily report, listing blocked messages sent to them, and a way to access/release a particular message.
We have looked at services like Postini which has a nice end user interface (http://www.postini.com/images/screens/q_summary.gif) . This functionality is what management here has deemed necessary, they do not want messages blocked/filtered without some way for the users being able to access messages inadvertantly blocked.
I'm running 1.39b2 on R6.5 with Baysean filtering and it works well, but before it would be allowed to be in production here, our users would need a way to notified and be able to access messages that get blocked. Of course the users would need to be allowed to view only their messages