Dramatically reduce memory footprint by changing the number of threads that spamassassin will execute at once from 5 down to 1.
Centos: In /etc/sysconfig/spamassassin –
change:
SPAMDOPTIONS="-d -c -m5 -H"
to
SPAMDOPTIONS="-d -c -m1 -H"
Debian: in /etc/default/spamassassin, change:
OPTIONS="--create-prefs --max-children 5 --helper-home-dir"
to
OPTIONS="--create-prefs --max-children 1 --helper-home-dir"