I wrote before about cleaning up the mail queue. I had a large queue today though and the exim tools “felt” slow. So I did it manually (which wasn’t much faster):
cd /var/spool/exim/input/
for d in *; do echo in $d; cd /var/spool/exim/input/$d; C=0; for x in *H; do grep -q example.com $x; if [ $? -eq 0 ]; then f=${x%H}; (( C++ )); rm ${f}{H,D}; fi; done; echo $C mails deleted; echo "remaining: "; ls -l | wc -l; echo ---; done