postgrey software package provides greylisting implementation for Postfix, you can install in your Ubuntu 14.04 LTS (Trusty Tahr) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install postgrey
postgrey is installed in your system.
Make ensure the postgrey package were installed using the commands given below,
$ sudo dpkg-query -l | grep postgrey *
You will get with postgrey package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | |
| Package | postgrey |
| Version | 1.34-1.2 |
| Description | greylisting implementation for Postfix |
| Sub Section |