Official guide : https://help.directadmin.com/item.php?id=36

If cpan is not found :

yum install perl-CPAN


Check again cpan :

[server]# cpan
cpan> o conf prerequisites_policy follow
cpan> o conf commit
cpan> quit


Then install the required modules:

cpan -i Archive::Tar Digest::SHA Net::DNS Net::DNS::Resolver::Programmable Mail::SPF Geo::IP Net::CIDR::Lite IO::Socket::IP \
IP::Country Net::Ident Net::Patricia IO::Socket::INET6 Compress::Zlib Mail::DKIM LWP::UserAgent HTTP::Date Encode::Detect ExtUtils::MakeMaker \
NetAddr::IP Mail::SpamAssassin::Plugin::Razor2 Razor2::Client::Agent IO::Socket::SSL DBI Sys::Syslog DBD::File


Run this command :

spam.sh


if spam.sh not found :

cd /usr/local/directadmin/scripts/
./spam.sh


Use CustomBuild to install SpamAssassin:

cd /usr/local/directadmin/custombuild
./build set spamd spamassassin
./build spamassassin


Or, some CustomBuild use this

./build set spamassassin yes


Go to exim configuration :

cd /etc/exim.conf


Search and uncomment (remove # ) at /etc/exim.spamassassin.conf :

.include_if_exists /etc/exim.spamassassin.conf


Restart exim :

service exim restart


Once setup, spamd should be running :

[root@cld01 custombuild]# ps ax |grep spamd
24269 ? Ss 0:01 /usr/bin/spamd -d -c -m 5
24285 ? S 0:00 spamd child
24286 ? S 0:00 spamd child
24829 pts/1 S+ 0:00 grep spamd


Verify at DirectAdmin