MacIntoshes

[Peter L. Peres]

On Wed, 1 Oct 2003, JoeHill wrote:

> On Wed, 1 Oct 2003 20:33:53 +0300 (IDDT)
> "Peter L. Peres" <plp-ysDPMY98cNQDDBjDh4tngg at public.gmane.org> uttered:
>
> > What nightmare ?! Having a registered domani name for use on the
> > internet is mandatory. You can't just make one up. 99% of spam exsists
> > because this rule is not enforced. I use postfix on my desktop as MTA
> > and it masquerades all my internal domain names to external. What's so
> > hard ?
>
> Whoa, easy there! I was under the impression that, even with a valid
> domain name, the RBLs will blacklist you because you are coming from a
> block of IP's that belong to an ISP, ie. you are considered an
> "amateur".

Mailhops are dumb pieces of equipment humming along in air-conditioned
rooms. They do not consider things. They check that the ip of the previous
mailhop matches its name (the one it gives in the helo smtp line). Then,
if more bsod style setup, they check that *each* mailhop name in the
message maps to a real ip. Therefore if a unregistered domain appears
anywhere in the envelope the mail could be deleted as spam. Therefore you
do not put any unregistered domain in there. So you translate (masquerade)
each unregistered name at domain to the ones you are really registered as at
the isp you are using.

But many organisations hide their desktops behind routers and firewalls so
there is no way for a server to check all the envelope names against their
ips. So this feature mostly does not work because everyone disables it.
That's why hard-to-trace spam can exist.

Half the denied pings I get here come from ips that cannot be named.

> If you want to be absolutely sure to remain *off* of the RBL's, you need
> a registered mail server, like mail.whatever.com, at least that's the
> impression I got from what I've read.

Unfortunately, no. Just make sure that what you send matches the domain of
the server you are connecting to.

> And if spam is not a nightmare, I don't know what is... ;-)

More spam, or a blackout at the wrong time, or both of these thing. I can
also think of another 5-600 things that are pretty bad if you want.

Peter
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