The following is from the postfix-3.6-20210221 release notes.
Wietse
Postfix version 3.6 deprecates terminology that implies white is
better than black. Instead, Postfix prefers 'allowlist', 'denylist',
and variations on those words.
Noel Jones assisted with the initial transition.
Changes in documentation
------------------------
Documentation was updated to use 'allowlist', 'denylist', etc.
These documentation changes do not affect Postfix behavior.
Changes in parameter names
--------------------------
The following parameters replace names that contain 'blacklist' or
'whitelist':
postscreen_allowlist_interfaces
postscreen_denylist_action
postscreen_dnsbl_allowlist_threshold
These new parameters have backwards-compatible default settings
that support the old parameter names, so that the name change should
not affect Postfix behavior. This means that existing management tools
that use the old parameter names should keep working as before.
This compatibility safety net may break when some management tools
use the new parameter names, and some use the old names, such that
different tools will disagree on how Postfix works.
Changes in logging
------------------
The following logging replaces forms that contain 'blacklist' or
'whitelist':
postfix/postscreen[pid]: ALLOWLIST VETO [address]:port
postfix/postscreen[pid]: ALLOWLISTED [address]:port
postfix/postscreen[pid]: DENYLISTED [address]:port
To avoid breaking logfile analysis tools, Postfix keeps logging the old
forms by default, as long as the compatibility_level parameter setting
is less than 3.6, and the respectful_logging parameter is not explicitly
configured. As a reminder, Postfix will log the following:
postfix/postscreen[pid]: Using backwards-compatible default setting
respectful_logging=no for client [address]:port
To keep logging the old form, make the setting "respectful_logging =
no" permanent in main.cf, for example:
# postconf "respectful_logging = no"
# postfix reload
To stop the reminder, configure the respectful_logging parameter to
"yes" or "no", or configure "compatibility_level = 3.6".
