[Mailman-Users] Scrubbing attachments only if over size limit - Umbrella list

[Dave Nathanson]

I've spent almost 2 whole days reading the MailMan FAQ, Googleing and  
testing theories/methods with a set of test-lists. I am using MailMan  
2.1.12 installed at DreamHost.com. I do not have root access. Although  
I can ssh into the server, I'm not good at writing shell scripts.  
Sorry if this looks long or wordy, I'm trying to give enough info to  
get some help.

What I am trying to do is allow list members to post plain text, or  
html messages, and attachments up to a set size. Any attachments  
larger than that size, I'd like to be scrubbed and a link url inserted  
so the list members don't have to download some stupid cat video just  
to unclog their mail delivery, but those who love cat videos can just  
click the link and get it.

I understand the attachment scrubbing feature. It is useful. But it  
will only scrub ALL messages not just those over a certain size. And  
it takes out the html that people are using so much more than they  
used to. Ideally, I would love to have the attachment scrubbing  
feature operate only on messages larger than a certain size. That  
would solve my entire problem.

One of the lists I admin includes decidedly non-technical people who  
think nothing of forwarding 12 mb attachments. They don't understand  
why this is not allowed, and I'm getting tired of explaining it again.  
These same people are not interested (or capable) of uploading their  
large attachment to a server and emailing a link to the list. So I'm  
trying to help them, but without relaying huge attachments to the list.

So after much reading, I got the idea of using an umbrella list set to  
scrub attachments to give users the option of sending their huge  
attachments and it will auto-generate a link. Lovely. But I'm not  
having success in implementation. Perhaps you can help me with this.

I made 2 MailMan lists:

* regular_list  (restricted by size less than 2 mb). Has membership.
* big_list (no size restriction), set to scrub attachments. No  
members, should send to/from the members of the regular list. Set to  
be an umbrella list.

THEORY:
The way I expect this to work is the list member will send his huge  
attachment to the regular_list, it bounces back, and tells him to try  
sending it to the big_list instead. This ought to scrub the  
attachment, leaving a URL instead, and lets the msg continue to the  
regular_list where it will now be well under the size restriction and  
pass through to all the members of regular_list.

Am I on track?
I just want 2 lists, with the exact same membership list, one to scrub  
attachments, and the other to reject oversize attachments. Both should  
only accept postings from list members.

The problem is that the regular_list is not accepting messages  
addressed to the big_list. I searched the list archives and found some  
interesting info, but maybe I've read so much that I can't see or  
think straight anymore. I read the articles:
3.5. What is an Umbrella list - and why doesn't it do what I want?
3.69. How do I set up an umbrella list?

But I have not been successful in getting the umbrella list concept to  
work.

What is the trick? Is this possible? Is there a better way? What needs  
to be typed where?

Thanks,
  Dave