Add this code to qmail service startup file.

if [ -f /var/qmail/control/spamhaus ]; then
   rblsmtpd="/usr/local/bin/rblsmtpd -r sbl-xbl.spamhaus.org"
else
   rblsmtpd="/usr/local/bin/rblsmtpd -r cbl.abuseat.org -r dul.dnsbl.sorbs.net -r http.dnsbl.sorbs.net -r misc.dnsbl.sorbs.net -r smtp.dnsbl.s
orbs.net -r socks.dnsbl.sorbs.net \
      -r spam.dnsbl.sorbs.net -r web.dnsbl.sorbs.net -r zombie.dnsbl.sorbs.net"
fi