How To Install exim-greylist on CentOS 7

In this tutorial we learn how to install exim-greylist on CentOS 7. exim-greylist is Example configuration for greylisting using Exim

Introduction

In this tutorial we learn how to install exim-greylist on CentOS 7.

What is exim-greylist

This package contains a simple example of how to do greylisting in Exim’s ACL configuration. It contains a cron job to remove old entries from the greylisting database, and an ACL subroutine which needs to be included from the main exim.conf file. To enable greylisting, install this package and then uncomment the lines in Exim’s configuration /etc/exim.conf which enable it. You need to uncomment at least two lines – the ‘.include’ directive which includes the new ACL subroutine, and the line which invokes the new subroutine. By default, this implementation only greylists mails which appears ‘suspicious’ in some way. During normal processing of the ACLs we collect a list of ‘offended’ which it’s committed, which may include having SpamAssassin points, lacking a Message-ID coming from a blacklisted host, etc. There are examples of these in the default configuration file, mostly commented out. These should be sufficient for you to you trigger greylisting for whatever ‘offences’ you can dream of, or even to make greylisting unconditional.

We can use yum or dnf to install exim-greylist on CentOS 7. In this tutorial we discuss both methods but you only need to choose one of method to install exim-greylist.

Install exim-greylist on CentOS 7 Using yum

Update yum database with yum using the following command.

sudo yum makecache

After updating yum database, We can install exim-greylist using yum by running the following command:

sudo yum -y install exim-greylist

Install exim-greylist on CentOS 7 Using dnf

If you don’t have dnf installed you can install DNF on CentOS 7 first. Update yum database with dnf using the following command.

sudo dnf makecache

After updating yum database, We can install exim-greylist using dnf by running the following command:

sudo dnf -y install exim-greylist

How To Uninstall exim-greylist on CentOS 7

To uninstall only the exim-greylist package we can use the following command:

sudo dnf remove exim-greylist

References

Summary

In this tutorial we learn how to install exim-greylist on CentOS 7 using yum and dnf.