where should the whitelist files be placed actually ?

[j75]

In the commented lines at the beginning of the postgrey_whitelist_recipients and postgrey_whitelist_clients files it is stated that both files should be placed in the /etc/postfix folder ; on Debian 11 these comments are changed and they claim that the folder should be .etc/postgrey. Is that an error somewhere, either in Debian or here, or Debian has a modification with respect to this project?

[fleish]

It depends how you have installed postgrey.

If you used the files in git the default file location is set to /etc/postfix

The Debian & Ubuntu packages I'm using appear to set the default file location to /etc/postgrey

You can also call postgrey -h which will show you these defaults for the various configuration files.

[j75]

Thanks!