Install Postfix

Installing Postfix

Uninstall SendMail

1. Run the command below to ensure that SendMail is removed/not installed

yum remove sendmail

Install Postfix

1. Install Postfix with the below command
   
   yum install postfix
   
   
2. Make postfix as default MTA for your system using the following command
   
   alternatives --set mta /usr/sbin/postfix

Use the command below, if the above command does not work

alternatives --set mta /usr/sbin/sendmail.postfix

Start and Enable Postfix

1. With the below commands, start and enable Postfix

Start Postfix
=============

service postfix start

Enable Postfix
==============

chkconfig postfix on

Open Firewall Port

1. Open the firewall with the below commands to allow Postfix to communicate

iptables -A INPUT -m state --state NEW -m tcp -p tcp --dport 25 -j ACCEPT
iptables -A INPUT -m state --state NEW -m udp -p udp --dport 25 -j ACCEPT