postgrey via systemctl doesn't create socket

If I run it /usr/sbin/postgrey with parameteres it works as usual. If i use /etc/init.d/postgrey restart or systemctl restart postgrey - it doesn't.

It looks like it doesn't read /etc/default/postgrey at all, but how to debug this? And if so, how to force it?

/etc/default/postgrey:

POSTGREY_OPTS="--unix /var/spool/postfix/postgrey/socket"