Для установки amavisd-new, spamassassin и clamav, выполните следующую команду:

yum install amavisd-new spamassassin clamav clamd unzip bzip2 unrar perl-DBD-mysql

Затем стартуем freshclam, amavisd, и clamd...

chkconfig --levels 235 amavisd on
chkconfig --levels 235 clamd on
/usr/bin/freshclam
/etc/init.d/amavisd start
/etc/init.d/clamd start

... и создадим несколько необходимых папок:

mkdir /var/run/amavisd /var/spool/amavisd /var/spool/amavisd/tmp /var/spool/amavisd/db
chown amavis /var/run/amavisd /var/spool/amavisd /var/spool/amavisd/tmp /var/spool/amavisd/db