[Mailman-Users] Massive list prevents other lists' posts?

[Neil Kandalgaonkar]

We're using Mailman to manage many lists. Our announcement list
is very large, 50,000+ users. 

Whenever we post a message to the very large list, posts stop
flowing from the others.

I've looked through the Mailman source to figure out why, and I'm stumped.
It seems to me that nothing should be impeding the other lists from 
injecting their messages into the queue, interleaved with the mass 
mailout from the announcement list.

If I add a new member to a list, that member gets their welcome message
instantly. So there isn't a fundamental resource limitation here. A post
to that list, however, doesn't get through.

Any suggestions on how to fix this?

-- 
Neil Kandalgaonkar
Web App Developer, ActiveState