hapolicy software package provides Balancing and fallback postfix policy delegation service, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install hapolicy
hapolicy is installed in your system.
Make ensure the hapolicy package were installed using the commands given below,
$ sudo dpkg-query -l | grep hapolicy *
You will get with hapolicy package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | |
| Package | hapolicy |
| Version | 1.35-3 |
| Description | Balancing and fallback postfix policy delegation service |
| Sub Section |