To do this, you would edit /etc/sysconfig/spamassassin and
adjust the -m option to your liking. For instance, if you wanted to
increase the SA children from 5 (the default) to 10, you would modify
the following line:
SPAMDOPTIONS=”-d -c -m5 -H” to read:
SPAMDOPTIONS=”-d -c -m10 -H”