$ sudo apt-get update
$ sudo apt-get install mysqmail-postfix-logger 

mysqmail-postfix-logger is installed in your system.

Make ensure the mysqmail-postfix-logger package were installed using the commands given below,

$ sudo dpkg-query -l | grep mysqmail-postfix-logger *

You will get with mysqmail-postfix-logger package name, version, architecture and description in a table

mysqmail-postfix-logger package basic information: