currently logging in PFA can only be enabled or disabled. For privacy reasons it would be useful if the logging of IP addresses could be switched on/off in the config file. The IP address is currently stored in the logs together with the username.
There's one thing I don't understand in your request: What is the advantage of not logging the IP address?
I'd understand the request for an anonymous service (which we obviously can't have for mailserver configuration) - but since we log the username (which allows to identify an user), I see no privacy advantage in not logging the IP.
Therefore I tend to reject this request - unless you tell me what I overlooked ;-)
no reply for a long time, therefore marking as wontfix as promised ;-) in my previous comment