[Lias] Postfix Problem.

[Ken Yap]

>Hey all,
>
>I am having a problem setting up Postfix on RedHat 9. I have set it up
>to reject_unknown_hostname for smtpd_helo_restrictions. Now when I
>send
>an email via telnet this is what i get:
>
>> helo iona.qld.edu.au
>....
>450 <iona.qld.edu.au>: Helo command rejected: Host not found
>
>I tried others like microsoft.com but it does the same thing. It
>doesnt
>seem to be doing a lookup.
>
>Does anyone have any ideas?

The domain name is not getting looked up. But...

even if you get this to work, you will find lots of senders do not put a
FQDN after HELO. It's controversial whether if they have to according to
the RFC, but the fact is, many legit senders don't.

RBL and DSBL catches about 80% of spam, mostly from zombies. Helo is
myself catches another 15% or so.