Reinstall yum package

as you might know, yum does not provide re-install functionality,

for re-installing yum installed application following methods may useful

yum install yum-utils
yumdownloader package
rpm -Uvh –force downloadedpackages

Install Postgrey on CentOS

Activate dag repository

name=Dag RPM Repository for Red Hat Enterprise Linux

install package

root@ns99 ~ # yum install postgrey

edit startup script /etc/init.d/postgrey

OPTIONS=”–whitelist-clients=/etc/postfix/postgrey_whitelist_clients –whitelist
   recipients=/etc/postfix/postgrey_whitelist_recipients –inet=10023 -d –unix=$SOCKET”

startup postgrey when system is bootup

 root@ns99 ~ # chkconfig postgrey on

install filter to postfix /etc/postfix/

smtpd_recipient_restrictions = permit_mynetworks, reject_unauth_destination, check_policy_service inet:

edit white-list as you need /etc/postfix/postgrey_whitelist_clients

Check delay from maillog

cat /var/log/maillog | postgreyreport 

Install SPF to CentOS Postfix

In computingSender Policy Framework (SPF) allows software to identify messages that are or are not authorized to use the domain name in the SMTP HELO and MAIL FROM (Return-Path) commands, based on information published in a sender policy of the domain owner. Forged return paths are common in e-mail spam and result inbackscatter. SPF is defined in RFC 4408. from wikipedia

Install require packages

root@ns99 ~ # yum install perl-Mail-SPF

Get SPF module from Newest at this time is 2.007 and Install SPF module

root@ns99 ~ # wget root@ns99 ~ # tar zxvf postfix-policyd-spf-perl-2.007.tar.gz root@ns99 ~ # mv postfix-policyd-spf-perl-2.007/postfix-policyd-spf-perl /usr/local/lib.

add following line to /etc/postfix/

policy  unix  –       n       n       –       0       spawn
  user=nobody argv=/usr/bin/perl /usr/local/lib/policyd-spf-perl

add following line to /etc/postfix/

smtpd_recipient_restrictions = permit_mynetworks, reject_unauth_destination, check_policy_service,
check_policy_service unix:private/policy
policy_time_limit = 3600

Add SPF record to your DNS. SPF record can be wizardly made from

spf01   IN TXT “v=spf1 ~all”
spf02   IN TXT “v=spf1 +ip4:yyy.yyy.yyy.yyy/24  ~all”
@       IN TXT “v=spf1 ~all”

Rebuild apache rpm on Centos4

Download src rpm

Install src rpm
ns2 ~ # rpm -ivh httpd-2.0.63-2.el4s1.centos.2.src.rpm
ns2 ~ # cd /usr/src/redhat/SPECS
ns2 SPECS # vim httpd.spec
%define contentdir /var/www -> %define contentdir /home
ns2 SPECS # rpmbuild -bb /usr/src/redhat/SPECS/httpd.spec
error: Failed build dependencies:
xmlto >= 0.0.11 is needed by httpd-2.0.63-2.el4s1.centos.2.i386
apr-devel >= 0.9.4-20 is needed by httpd-2.0.63-2.el4s1.centos.2.i386
apr-util-devel is needed by httpd-2.0.63-2.el4s1.centos.2.i386
distcache-devel is needed by httpd-2.0.63-2.el4s1.centos.2.i386
Install missing packages
ns2 SPECS # yum install xmlto apr-devel apr-util-devel distcache-devel
ns2 SPECS # rpmbuild -bb /usr/src/redhat/SPECS/httpd.spec
ns2 SPECS # cd ../RPMS
ns2 RPMS # rpm -ivh –force httpd-2.0.63-2.el4s1.centos.2.i386.rpm
ns2 ~ # /etc/init.d/httpd restart
ns2 ~ # suexec -V