Description of problem:
A common user scenario is to be able to reset configuration to the defaults.
When running `postconf -d` to receive default values, `postconf` prints upstream defaults. However, in RHEL, some defaults settings are different from the upstream defaults. Hence, it is impossible to get the real default settings for some parameters.
The fault defaults can be found by running `postconf -n` that prints settings that are different from the defaults. 

Version-Release number of selected component (if applicable):
postfix-3.5.8-2.el8.x86_64.rpm

How reproducible:
Always

Steps to Reproduce:
1. Install postfix
2. Enter `postconf -d` to find the default settings
3. Enter `postconf` to find the current settings

Actual results:
Some values at the output of `postconf -d` and `postconf` are different.

Expected results:
The outputs of `postconf -d` and `postconf` must be the same because we have just installed the package and did not change any settings.

Additional info:
The script that compares outputs of two commands and prints settings that are different:
~~~
#!/bin/bash
settings_to_apply=__postconf_settings_to_apply.txt
current_settings=__postconf_current.txt
default_settings=__postconf_defaults.txt
postconf > $current_settings
postconf -d > $default_settings
while read line; do
  if ! grep -Fxq "$line" $current_settings; then
    echo $line >> $settings_to_apply
  fi
done < $default_settings
cat $settings_to_apply
~~~

I think that the settings are rewritten in the spec file here but I might be wrong:
https://src.osci.redhat.com/rpms/postfix/blob/rhel-9.0.0/f/postfix.spec#_356