post_install() {
	if ! getent group postgrey &>/dev/null; then
		groupadd -r postgrey >& /dev/null
	fi
 	if ! getent passwd postgrey &>/dev/null; then
		useradd -r -d /var/spool/postfix/postgrey -g postgrey -s /bin/false postgrey
	fi

	chown postgrey:postgrey /var/lib/postgrey
}

post_upgrade() {
	post_install $1
}

post_remove() {
	if getent passwd postgrey &>/dev/null; then
		userdel postgrey >/dev/null
	fi
	if getent group postgrey &>/dev/null; then
		groupdel postgrey >/dev/null
	fi
}