Enabling logging of Spamassassin actions on a server with DirectAdmin is rather simple, so here is how to do that.
Update /etc/init.d/exim and replace
if [ -e /usr/bin/spamd ]; then /usr/bin/spamd -d -c -m 15 1>/dev/null 2>/dev/null; fi
with
if [ -e /usr/bin/spamd ]; then /usr/bin/spamd -d -c -m 5 -s /var/log/exim/spamd.log -r /var/run/spamd.pid 1>/dev/null 2>/dev/null; fi
and re-start exim. To test see:
# ps aux | grep spam root 2494 0.0 1.5 257008 61264 ? SN May12 0:21 spamd child root 3902 0.0 1.4 254980 58744 ? SN May12 0:06 spamd child root 13854 0.0 1.4 252108 56260 ? SNs May12 0:26 /usr/bin/spamd -d -c -m 5 -s /var/log/exim/spamd.log -r /var/run/spamd.pid root 18952 0.0 0.0 103308 844 pts/3 SN+ 00:21 0:00 grep spam
You might need to create /var/log/exim/spamd.log prior to exim restart and take care of it's rotation.