Wietse Venema:
> > After I ran this (in fact I was too slow ;-) ), I sent a mail from
> > external MTA mail.sys4.de and this mail did not run through any
> > of the milters. It is much more worse than I thought, because each
> > mail after that "mail loop" above was not scanned by any milters
> > anymore! I also stopped postfix and started it again and still no
> > milters got connected when sending test mails from external MTA.
>
> If this problem persists after stopping and starting Postfix, then
> you have proved that either it is not a Postfix problem or that your
> measurement procedure is in error.
>
> There is no POSTFIX Milter-related state that persists across
> restarts, but there may be such state elsewhere: rate-limiting
> policy servers, state in the kernel's networking stack, clients
> deciding to deliver mail elsewhere, ...
Especially relevant for logging is system-effing-d log rate limiting,
which reportedly has lower thresholds than rsyslog log rate limiting,
meaning that systemd throws away events before rsyslogd can log them.
This mechanism persists across Postfix restarts.
Wietse
