that is the only thing I found under postconf:
unknown_client_reject_code = 450

Greg Hackney wrote:
> rogv24@yahoo.com wrote:
>
> > I did a postconf and i didn't even see reject_unknown_client.
>
> You'll see it in "man 5 postconf".
>
> It won't appear in the output of "postconf" until you actually
> use it in the configuration. What you will be able to see with
> postconf, is the heading that it usually goes under,
> smtpd_client_restrictions
>
>
> > So I guess I have to wait.
>
> No waiting, it's there. It was there in Version 1.something.
>
>
> > Is it best to reinstall Postfix with the new version or upgrade?
>
> I've since forgotten what OS you are running, but with Linux it
> doesn't matter whether you upgrade from an RPM or distribution
> package, or do a "make install" from the source code, it won't
> blow away your configs in /etc/postfix. But it's smart to
> always back up those files anyway.
>
> --
> Greg