Spamassassin

General Improvements

Add razor, dcc and pyzor

Step 1) Add atomic channel:

 wget -q -O - http://www.atomicorp.com/installers/atomic.sh |sh

Step 2) Add razor, dcc, pyzor

 yum install razor-agents dcc pyzor

Step 3) Restart spamassassin

 /etc/init.d/spamassassin restart

Force spamassassin to scan messages from localhost, when using qmail-scanner

 vi /etc/xinetd.d/smtp_psa

service smtp
{
       socket_type     = stream
       protocol        = tcp
       wait            = no
       disable         = no
       user            = root
       instances       = UNLIMITED
       env             = QS_SPAMASSASSIN="on"
       server          = /var/qmail/bin/tcp-env
       server_args     = /usr/sbin/rblsmtpd -r sbl-xbl.spamhaus.org /var/qmail/bin/relaylock /var/qmail/bin/qmail-smtpd /var/qmail/bin/smtp_auth /var/qmail/bin/true /var/qmail/bin/cmd5checkpw /var/qmail/bin/true
}

Mysql settings for whitelisting

INSERT INTO userpref (username,preference,value) VALUES ('%tsginc.com','whitelist_from','*domain.com');
INSERT INTO userpref (username,preference,value) VALUES ('%tsginc.com','whitelist_from','*@domain.com');

Limiting Load

Add max_load to /etc/xinetd.d/smtp_psa. SMTP will throttle connections when load reaches a certain point. The per_source flag will limit the maximum number of concurrent connections from a single IP.

service smtp
{
       socket_type     = stream
       protocol        = tcp
       wait            = no
       disable         = no
       user            = root
       max_load        = 5
       per_source      = 2
       instances       = UNLIMITED
       env             = QS_SPAMASSASSIN="on"
       server          = /var/qmail/bin/tcp-env
       server_args     = /usr/sbin/rblsmtpd -r sbl-xbl.spamhaus.org /var/qmail/bin/relaylock /var/qmail/bin/qmail-smtpd /var/qmail/bin/smtp_auth /var/qmail/bin/true /var/qmail/bin/cmd5checkpw /var/qmail/bin/true
}