milter-greylist command not found

Introduction

When you run more command in linux terminal / console, you get the following error message

milter-greylist: command not found

or when using sudo you get the following error message

sudo: milter-greylist: command not found

Solutions to milter-greylist: command not found

How To Fix milter-greylist: command not found in Ubuntu / Debian / Kali Linux / Raspbian

In Ubuntu milter-greylist is provided by milter-greylist package.

milter-greylist is:

milter-greylist is a stand-alone milter written in C that implements the greylist filtering method, as proposed by Evan Harris.

Greylisting works by assuming that unlike legitimate MTA, spam engines will not retry sending their junk mail on a temporary error. The filter will always temporarily reject mail on a first attempt, and to accept it after some time has elapsed.

If spammers ever try to resend rejected messages, we can assume they will not stay idle between the two sends (if they do, the spam problem would just be solved). Odds are good that the spammer will send a mail to an honey pot address and get blacklisted in several real-time distributed black list before the second attempt.

To fix this problem, we can install more using the command below.

sudo apt-get -y install milter-greylist

This command might take some time to finish depending on your machine internet connection.

You can also use apt command to install milter-greylist.

sudo apt -y install milter-greylist

Or if you have aptitude installed you can use the following command.

sudo aptitude install milter-greylist

Summary

In this tutorial we learn how to fix milter-greylist command not found error in Ubuntu / Debian / Kali Linux or Raspbian distribution.