How To Install Exim Mail Server on CentOS 6

In this tutorial, we will show you how to install Exim Mail Server on CentOS 6. For those of you who didn’t know, Exim is a mail transfer agent (MTA) used on Unix-like operating systems. Exim is free software distributed under the terms of the GNU General Public License, and it aims to be a general and flexible mailer with extensive facilities for checking incoming e-mails. The Exim security record is much better than Sendmail. Advanced features are queue handling, address routing, and testing.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple. I will show you the step-by-step installation of Exim on CentOS 6.

Prerequisites

• A server running one of the following operating systems: CentOS 6.
• It’s recommended that you use a fresh OS install to prevent any potential issues.
• SSH access to the server (or just open Terminal if you’re on a desktop).
• A non-root sudo user or access to the root user. We recommend acting as a non-root sudo user, however, as you can harm your system if you’re not careful when acting as the root.

Install Exim Mail Server on CentOS 6

Step 1. First, we need to install the latest EPEL repository RPM suited to your architecture.

## RHEL/CentOS 6 64-Bit ##
# wget http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
# rpm -ivh epel-release-6-8.noarch.rpm

## RHEL/CentOS 6 32-Bit ##
# wget http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
# rpm -ivh epel-release-6-8.noarch.rpm

Step 2. Install the Exim package.

Run the following command to install Exim:

yum install exim-mysql -y

Step 3. Disable Postfix (the default MTA).

By default, CentOS uses Postfix as MTA. Follow is how to disable and enable Exim on CentOS. First, we stop the service and disable postfix for autostart:

service postfix stop
chkconfig postfix off

Step 4. Set Exim as the default MTA.

Next, we change the default Postfix MTA to Exim. Press “2” enter to select Exim:

# alternatives --config mta
There are 2 programs which provide 'mta'.

  Selection    Command
-----------------------------------------------
*+ 1           /usr/sbin/sendmail.postfix
   2           /usr/sbin/sendmail.exim
Enter to keep the current selection[+], or type selection number: 2

Step 5. Start the Exim service.

chkconfig exim on
service exim start

Step 6. Accessing Exim.

Now you are done with Exim installation. Let’s verify if the MTA working as expected:

$ echo 'Hello, welcome to the jungle exim MTA' | mail -s 'Exim testing email' 
# tail -F /var/log/exim/mainlog

Congratulations! You have successfully installed Exim. Thanks for using this tutorial for installing Exim Mail Server on CentOS 6 systems. For additional help or useful information, we recommend you to check the official Exim website.