Simple Email Blacklist Using Spamassassin Plugin And RBLDNSD


This is not new idea, actually. someone at spamassassin plugin developers have been made before. basically, the idea was put email addresses in RBLDNSD zone dnset format, ie:



So, we replace @ sign into dot (.) sign. that way, we can save the email addresses into the RBLDNSD dnset zone.


create emailbl zone, meta information


: $ - Not receiving email right now.


$NS 1w
$SOA 1w 0 2h 2h 1w 1h
$DATASET generic @
@ A
@ MX 10
@ TXT "example email blocklist"

in /etc/sysconfig/rbldnsd

RBLDNSD="dsbl -r/var/lib/rbldns/dsbl -t 300 -b \,emailbl

ofcourse we should delegate the subdomain in authoritative nameserver

; subdomain delegation	IN NS			IN A

start rbldnsd service

service rbldnsd start

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Postfix, Rate Limiting Inbound Emails Using SenderScore And Memcache


I received email from someone fiew days ago, he directed me to an article about senderscore and and asked if I could make it usable. Actually, I’m not very familiar with how senderscore work. I’ve read the article and see the FAQ at I have found that senderscore can be queried with a format like this:

Ie, I want to know the score value of ip address, the format of the query would be like this:

$ dig a +short

Look at the answers given by senderscore’s NS. last octet is the score of the ip address, which scored 75.

Excerpts from senderscore faq:

All scores are based on a scale of 0 to 100, where 0 is the worst, and 100 is the best possible score. A score represents that IP address’s rank as measured against other IP addresses, much like a percentile ranking.

Now back to the article, The authors make a perl module that can perform queries to senderscore ns, put a “reputation score” into memcache, at the same time, calculating how many times an ip address connected to our smtp.

Let’s begin, first of all download Policy::Memcache from this git repository 
Create a working directory, and extract the tarball.

$ mkdir pol-mem && cd pol-mem
$ tar --extract --file=petermblair-libemail-f73612c.tar.gz petermblair-libemail-f73612c/perl/senderscore/memcache/
$ mv petermblair-libemail-f73612c/perl/senderscore/memcache/* .

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