[Mailman-Users] Topics and friendly rejections of topicless messages

[Patti Beadles]

I'm trying to set up a list with the topics feature, and I'm
having a little bit of trouble achieving what I want.  The
basic feature is fine, but making it a smooth user experience
is being problematic.  In particular, what I want is this:

A) Allow topic-based list subscription
B) Every message must have a topic
C) Messages that don't have a topic get bounced back to the user
D) The bounced messages must be "pretty", and explain what to do

A was easy enough.

I implemented B and C by using spam filtering, and setting the
spam filter to bounce mail whose subject line matches a regular 
expression.  That regex is essentially "not (topic1 | topic2)".
That solution is functional, if not particularly elegant.

Item D is throwing me for a loop.  I can make it happen with a
one-line change to SpamDetect.py, but that's probably not going
to fly.  The host runs multiple lists, and doing this would 
constrain the other lists in ways that aren't really acceptable.

I've wandered through this list's archives pretty extensively.
If this question has been answered then I haven't found the
right search incantation to get at the information.  Is there
a good way to accomplish what I'm trying to do?  Is there a way
to bounce spam to some particular email address, and run a 
script at that address to send back a pretty, helpful bounce?


The meta-problem that I'm trying to solve is this:  there's a
very active mailing list for people who attend a particular 
event.  Some members think that the list should only be about
the event and related topics, while others think that the list
is for general socialization among attendees of the event.
For the first group, there's disagreement about what related 
topics would be.

There's no split that seems to make sense.  Topics is the perfect
feature if I can get it to do what I want, but it's being a bit
finicky.

-Patti