couriergrey software package provides Mail filter interface of Courier-MTA to support greylisting, you can install in your Ubuntu 16.10 (Yakkety Yak) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install couriergrey
couriergrey is installed in your system.
Make ensure the couriergrey package were installed using the commands given below,
$ sudo dpkg-query -l | grep couriergrey *
You will get with couriergrey package name, version, architecture and description in a table
| Distro | Ubuntu 16 10 yakkety yak |
| Section | Network |
| Package | couriergrey |
| Version | 0.3.2-5build1 |
| Description | Mail filter interface of Courier-MTA to support greylisting |
| Sub Section | Net |