How to know if I'm blacklisted

[Glenn Steen]

On 18/01/2008, Matt Kettler <mkettler at evi-inc.com> wrote:
> Glenn Steen wrote:
>
> >>
> >> So, using such validation to refuse mail is RFC non-compliant.
> >
> > The magic is in:
> > -----
> >              Note also that the HELO argument is still required to have
> >              valid <domain> syntax, since it will appear in a Received:
> >              line; otherwise, a 501 error is to be sent.
> > -----
>
> Fair enough, so you can deny it if it doesn't conform to the domain syntax.
>
>
> Note this doesn't mean it must be resolvable, or even be a valid domain, it just
> has to logically conform to the syntax requirements of a domain. "mail2.canal4"
> is valid domain syntax, even if it's not a valid domain.
>
>
> > ... which is a bit further down. Your quote below is in regard to
> > doing an MX lookup on the string.
>
> Or any DNS lookup. It would appear the only time you can refuse is if it's
> syntactically invalid.
>
Yes. Exactly. One such invalidity is to use an email address syntax
(... at ....), which an amazing amount of spam senders use that.
One can argue about what is deemed a valid domain name, from a
syntactical viewpoint.... For instance, a bare word (xxxxx) isn't
syntactically correct either. Fortunate that the RFCs are pretty clear
on that too:-)
Hm. Perhaps one shouldn't be talking about this in a public forum....
the B*stards might get a clue:-).

Cheers
-- 
-- Glenn
email: glenn < dot > steen < at > gmail < dot > com
work: glenn < dot > steen < at > ap1 < dot > se