Simple Email Blacklist Using Spamassassin Plugin And RBLDNSD

 amavisd-new, centos, dnsbl, email, filter, linux, perl, plugin, postfix  2 Responses »
Oct 192012
 

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:

Email
user@example.com

RBLDNSD
user.example.com

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

RBLDNSD part:

create emailbl zone, meta information

zone

:127.0.0.4:DNSBL. $ - Not receiving email right now.
example.user.gmail.com
example.user.rediffmail.com

meta

$NS 1w ns.example.com ns.example.com
$SOA 1w ns.example.com admin.example.com 0 2h 2h 1w 1h
$DATASET generic @
@ A 1.2.3.4
@ MX 10 mx.example.com
@ TXT "example email blocklist"

in /etc/sysconfig/rbldnsd

RBLDNSD="dsbl -r/var/lib/rbldns/dsbl -t 300 -b 1.2.3.4 \
emailbl.example.com:combined:meta,emailbl
"

ofcourse we should delegate the subdomain emailbl.example.com in example.com authoritative nameserver

; subdomain delegation
emailbl.example.com.	IN NS ns.example.com.
ns.example.com.			IN A 1.2.3.4

start rbldnsd service

service rbldnsd start

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Postfix Changing Outgoing IP By Time Interval Using TCP_TABLE And Perl

 email, linux, modules, perl, pop3, postfix, programming, sendmail, smtp  14 Responses »
Nov 152011
 

Someone asked me if i can make a perl scripts that can change the ip address based on time interval, say he want ip address 1.2.3.4 used within one hour, if done next ip address will be used within next one hour..and so on. when it came to highest number of ip address in array, they will be reset back to the start. first i suggest him to look at the articles i wrote. But then i decide to write Perl script which was made for the purposes mention above.

here we are..

Postfix section:

master.cf
127.0.0.1:2527 inet  n       n       n       -       0      spawn
          user=nobody argv=/etc/postfix/ip_by_time.pl

ip1  unix -       -       n       -       -       smtp
          -o syslog_name=postfix-ip1
          -o smtp_helo_name=smtp1.example.com
          -o smtp_bind_address=1.2.3.1

ip2  unix -       -       n       -       -       smtp
          -o syslog_name=postfix-ip2
          -o smtp_helo_name=smtp2.example.com
          -o smtp_bind_address=1.2.3.2

ip3  unix -       -       n       -       -       smtp
          -o syslog_name=postfix-ip3
          -o smtp_helo_name=smtp3.example.com
          -o smtp_bind_address=1.2.3.3

ip4  unix -       -       n       -       -       smtp
          -o syslog_name=postfix-ip4
          -o smtp_helo_name=smtp4.example.com
          -o smtp_bind_address=1.2.3.4
....
....

main.cf

transport_maps = tcp:[127.0.0.1]:2527
127.0.0.1:2527_time_limit = 3600s

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