[rt-users] aborting ticket creation via scrip

[O. Ododa]

I'm trying to find a way to get RT not to create a ticket when it 
receives an email that matches certain criteria (is in a specific queue, 
subject matches or doesn't match a regex, content lines match or don't 
match a specific regex).

I've written the scrip and if a given check fails, I 'return undef;', 
but RT creates the ticket anyway. Is there any way to avoid this? I've 
searched the archive, and have come up empty.
--
O. Ododa