$ sudo apt-get update
$ sudo apt-get install libpostfix-parse-mailq-perl 

libpostfix-parse-mailq-perl is installed in your system.

Make ensure the libpostfix-parse-mailq-perl package were installed using the commands given below,

$ sudo dpkg-query -l | grep libpostfix-parse-mailq-perl *

You will get with libpostfix-parse-mailq-perl package name, version, architecture and description in a table

libpostfix-parse-mailq-perl package basic information: