For centos you have to nuke these directories and their files
rm -rf rm -rf /etc/mail && rm -rf /etc/mail/spamassassin && rm -rf /etc/sysconfig/spamassassin
rm -f /usr/bin/spamassassin
rm -f /usr/bin/spamc
rm -f /usr/bin/spamd
rm -f /usr/lib/systemd/system/spamassassin.service
rm -rf /usr/share/doc/spamassassin-*
rm -f /usr/share/man/man1/sa-awl.1.gz
rm -f /usr/share/man/man1/sa-compile.1.gz
rm -f /usr/share/man/man1/sa-learn.1.gz
rm -f /usr/share/man/man1/sa-update.1.gz
rm -f /usr/share/man/man1/spamassassin-run.1.gz
rm -f /usr/share/man/man1/spamassassin.1.gz
rm -f /usr/share/man/man1/spamc.1.gz
rm -f /usr/share/man/man1/spamd.1.gz
rm -rf /usr/share/spamassassin
rm -rf /var/lib/spamassassin
rm -rf /var/run/spamassassin
Please think of changing os to ubuntu 20.04 or AlamaLinux 8.3 in future