This is a way to describe how spamdyke works

https://www.youtube.com/watch?v=tTrK6P_Ke_U

Spamdyke is a filter for monitoring and intercepting SMTP connections between a remote host and a qmail server. Spam is blocked while the remote server (spammer) is still connected; no additional processing or storage is needed. In addition to all of its anti-spam filters, spamdyke also includes a number of features to enhance qmail. Best of all, using spamdyke does not require patching or recompiling qmail!

Lets install it.


# fetch http://www.spamdyke.org/releases/spamdyke-5.0.1.tgz
# tar zxvf spamdyke-5.0.1.tgz
# cd spamdyke-5.0.1/spamdyke
# ./configure
# make
# make install

Now we need to copy and then edit the spamdyke.conf to enable logging.


# cp /root/spamdyke-5.0.1/documentation/spamdyke.conf.basic /usr/local/etc/spamdyke.conf
# vi /usr/local/etc/spamdyke.conf

Now change the following values under logging.


log-level=verbose
log-target=stderr
full-log-dir=/var/log/spamdyke

Now we need to configure spamdyke to accept TLS connections. Please uncomment both lines below.


tls-level=smtps
tls-certificate-file=/var/qmail/control/servercert.pem

Now lets create the logging directory and set permissions:


# mkdir /var/log/qmail/spamdyke
# chown -R qmaild:wheel /var/log/spamdyke

Now we're going to edit the qmail-smtpd/run file.


# vi /service/qmail-smtpd/run

Under the RBL section uncomment the following line:


RBLCMD2="/usr/local/bin/spamdyke -f /usr/local/etc/spamdyke.conf"

and then restart the qmail-smtpd service.


# svc -t /service/qmail-smtpd

Now check the service and make sure it's running.


# svstat /service/qmail-smtpd
/service/qmail-smtpd: up (pid 20708) 12 seconds

Optional: Adding Spamdyke recipient validation.

NOTE: If you decide to use validrcptto for validation of users you can skip the steps below. If for some reason validrcptto isn't working for you this would be another way to make user validation work.

Parts of this article were modified from this page:

http://www.spamdyke.org/documentation/README_spamdyke_qrv.html

It's impossible to overstate the complexity of qmail's recipient validation procedure. It is inexcusably complex, far beyond the point where anyone can be certain qmail's implementation is correct (and secure) in all cases. If you want to get a glimpse at how bad it is, take at look at the flowchart here. You'll see the flowchart is big, but the number of possible configurations is describes enormous: there are just under 165 thousand different paths through it (even more if the loops are followed multiple times). Fully testing spamdyke's reject-recipient filter requires checking every one of those paths -- this takes weeks to finish using spamdyke's test scripts. spamdyke-qrv begins its work at step 7 in the flowchart (steps 1, 2, 5 and 6 are assumed to have been performed by spamdyke before spamdyke-qrv was started).

spamdyke-qrv is intended to be run as root by marking the binary "setuid root". This is necessary because spamdyke typically runs as a non-root user and doesn't have access to all of the files needed to validate an address without root access.

Now lets start the installation:


# cd /usr/local/bin
# ln -s gcc46 gcc
# ln -s g++46 g++
# cd /usr/ports/distfiles/
# tar -xzvf spamdyke-5.0.1.tgz
# cd spamdyke-5.0.1/spamdyke-qrv
# ./configure --with-excessive-output --with-vpopmail-support VALIAS_PATH=/usr/home/vpopmail/bin/valias VUSERINFO_PATH=/usr/home/vpopmail/bin/vuserinfo
# Make
# make install

Check the install with:


# spamdyke-qrv -v -v domain.com username