[exim] reaction on a failed transport_filter

Hi guys,

I have a transport_filter that I run in my appendfile transport:

address_file:
   driver = appendfile
   delivery_date_add
   envelope_to_add
   return_path_add
   transport_filter = /usr/local/lib/eagleeye/filter-feedback.pl \
                      $message_id

When the transport_filter's exit code is non-zero, indicating an error,
the message gets stuck on the queue:

2004-12-10 19:13:37 +0100 1CcpBY-000BJu-Q3 ==
/var/spool/eagleeye/ham/eagleeye-ham.mbox <ham@???>
R=system_aliases T=address_file defer (-24): filter process failure 1
while writing to /var/spool/eagleeye/ham/eagleeye-ham.mbox

Is there a way I can ignore such errors and simply discard the message?
If not, how can I quickly delete them from the queue? There's no need to
inform the original sender via a bounce. I'm running exim v4.43.


Thanks for your help,
Patrick