/etc/rsyslog.d/postfix.conf is in postfix 2.11.3-1+deb8u2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | # Create an additional socket in postfix's chroot in order not to break
# mail logging when rsyslog is restarted. If the directory is missing,
# rsyslog will silently skip creating the socket.
$AddUnixListenSocket /var/spool/postfix/dev/log
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