[CentOS] What can I do to UNDERSTAND why I can't reach centos.org (but everyone else can)?

[m.roth at 5-cent.us]

Tilman Schmidt wrote:
> Am 28.02.2013 23:52, schrieb John R Pierce:
>> you can't parse the headers until you read them, and you can't read the
>> headers until you accept the incoming message.
>
> Not true. You can read the entire mail in the SMTP DATA phase and
> still reject it after the terminating single dot.
> Works perfectly fine on several MIMEDefang installations I set
> up to reject incoming mails containing malware or exceeding a
> certain SpamAssassin score.

Right, I meant to respond to that, but forgot before I got home.

Look, somehow, someone, somewhere, has to decide they're receiving spam
from an address... and the question is, *what* address. By trying to block
what are allegedly "open relays", they're *also* blocking very large
hosting and service providers, *all* of whose mail goes through that
gateway. What *should* be reported to be blocked is the domain that's
sending the spam.

Blocking an open relay should be done *only* on human investigation, to
see whether that's the majority of what's coming out of there, and
consideration of what the "relay" is, whether it's a known source, or an
innocent large provider.

     mark