... well, the subject says it: in a NULLCLIENT configuration, we want to have all normal users to be masqueraded
, but all system users should be exposed.
The sysadmins get system user's mails from a lot of different hosts, and want to see eg. lp@hostname.example.net
, instead of lp@example.net
, not knowing which host has printing issues.
We could script it to get all users < 1000 from /etc/passwd and filling masquerade_exceptions=
accordingly, but perhaps there is a more convenient way provided by postfix itself...?