/etc/init.d/exim stop;
sleep 10;
killall -9 exim eximd
sleep 5;

#clean out the mail queue
find /var/spool/exim -mindepth 2 -type f -exec rm -rf {} \;

#clean out the mail db files
find /var/spool/exim/db -type f -exec rm -rf {} \;

#reset the eximstats database tables
echo “truncate table sends;” | mysql eximstats
echo “truncate table defers;” | mysql eximstats
echo “truncate table failures;” | mysql eximstats
echo “truncate table smtp;” | mysql eximstats

/etc/init.d/exim restart