[Exim] Queue performance.

Hi all,

I'm experiencing serious delays in queue processing, whether local or
remote deliveries. If a client decided to send out a 500k file to 2000
of their closest friends, it takes hours and hours to clear manually
using various Exim queue runner combinations (ie. exim -Sff <whatever>,
exim -Rff <whatever>, exim -qqffl etc etc etc). I find myself doing
this daily, and frankly it's becoming unacceptable. Can anyone
recommend something to do, preferably something I can automate?

-- Steve