Hello, is there possibility how to integrate policyd-postfix or any other application securely into ispconfig architecture and GUI?
There are many threads about this on the forum, so search around a bit. I personally use rspamd which has a function for ratelimiting per ip, user, etc. If you are currently using amavis, see https://www.howtoforge.com/replacing-amavisd-with-rspamd-in-ispconfig/ on how to replace it.
yeah but there is no best practice made for actuall classical ISPConfig architecture (Amavis+postfix+dovecot+spamassasin)
What do you mean? Policyd is not part of such a "classical" setup either... And rspamd is installed by default in the new perfect server guide: https://www.howtoforge.com/ispconfig-autoinstall-debian-ubuntu/
You can use postfwd (example config is available in the issue tracker) or other policy daemons if you prefer another. There is not ui support for those or rspamd, it's all custom config.