[Mailman-Users] stopping a message post in progress?

[Wallace Winfrey]

Hello

We're running a list with about 1100+ subscribers, and this list is also 
integrated with some web forum software (FudForum, specifically).

Every once in a while, a spammer or someone else will post something 
inappropriate to the forum. Often times we will catch this post right 
away, before mailman has been able to send the post out to all our 
subscribers.

How might I prevent the post from going out to the rest of list? Is 
there any way to do this? Note, I'm not asking about emergency 
moderation, just how to stop a post in the progress of being sent out.

TIA,

w