March 16, 2017 Roberto Puzzanghera 4 comments
NB: you can skip this page if you decided to use qmail-dnsbl instead
A Realtime Blackhole List (RBL) is a list of addresses that an RBL list supplier believes are a source of Spam.
rblsmtpdblocks mail from RBL-listed sites. It works with any SMTP server that can run under
qmail-smtpd's run script is already set to run
qmail-smtpd. The following lines are related to
rblsmtpd (others are omitted):
# This enables greetdelay anti-spam functionality on rblsmtpd export GREETDELAY=15 # This disables rblsmtpd reject #export RBLSMTPD="" exec /usr/local/bin/softlimit -m "$SOFTLIMIT" \ /usr/local/bin/tcpserver -v -H -R -l 0 \ -x /home/vpopmail/etc/tcp.smtp.cdb -c "$MAXSMTPD" \ -u "$QMAILDUID" -g "$NOFILESGID" 0 25 \ /usr/local/bin/rblsmtpd -W \ -b -r zen.spamhaus.org \ -b -r bl.spamcop.org \ /var/qmail/bin/qmail-smtpd 2>&1
rblsmtpd is the first program who talks with the sender you may want to enable the GREETDELAY here and not inside
GREETDELAY=15 sets a delay of 15 seconds. In this example two different RBL sources will be queried. If their responce is ok the
qmail-smtpd program will be run.
rblsmtpd you have to delete the following lines from the code above:
/usr/local/bin/rblsmtpd -W \ -b -r zen.spamhaus.org \ -b -r bl.spamcop.org \
NB: If you decide to use
zen.spamhaus.org as suggested here, check the free use terms and be aware that exceeding these terms causes the cut off of your server. I think that one of my servers has been banned, since I can't resolve
Connect to Russel Nelson's http://www.crynwr.com/spam/ site and follow the instructions. In a few words you have to do a
telnet ns1.crynwr.com from your mail server and look if
spamhaus.org is working fine as a filter.
You may be interested at this point to take a look to the idea of Costel Balta, which is addressed to decrease the amount of connections to the RBL lists, avoiding to be banned consequently.
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