Sendmail RBL

cd /etc/mail vi sendmail.mc FEATURE(dnsbl, `dnsbl.sorbs.net', `RBL Rejected - see http://dnsbl.sorbs.net')dnl FEATURE(dnsbl, `rhsbl.sorbs.net', `RBL Rejected - see http://rhsbl.sorbs.net')dnl FEATURE(dnsbl, `bl.spamcop.net', `RBL Rejected - see http://bl.spamcop.net')dnl FEATURE(dnsbl, `zen.spamhaus.org', `RBL Rejected - see http://zen.spamhaus.org')dnl FEATURE(dnsbl, `ubl.unsubscore.com', `RBL Rejected - see http://blacklist.lashback.com')dnl m4 sendmail.mc > sendmail.cf /etc/init.d/sendmail restart

Add rbl list in sendmail.mc configration (before MAILER). Few days later , try check in log
cat /var/log/maillog |grep RBL