Install Spamassassin in Debian
#apt-get install spamassassin spamc
spamassassin package can also be integrated into a Mail Transport Agent such as postfix.
By default Spamassassin will run as root users when you install from debian repository and is not started to avoid that, we are going to create a specific user and group for spamassassin.
#groupadd -g 5001 spamd
#useradd -u 5001 -g spamd -s /sbin/nologin -d /var/lib/spamassassin spamd
#chown spamd:spamd /var/lib/spamassassin
Postfix and Spamassassin: How to filter spam