Merv
Thu Nov 20 22:31:16 CST 2003
Javier:
http://www.dnsstuff.com/
Enter 4.2.2.1 (Verizon DNS server) in the Reverse DNS Lookup section. This
gives an explanation of how reverse DNS is determined. It's based on
searching the root servers for PTR records.
Description of DNS Reverse Lookups
http://support.microsoft.com/?kbid=164213
How does DNS work
http://cr.yp.to/djbdns/intro-dns.html
http://www.zonecut.net/dnsgeo/index.html
Are we on the right track here?
--
Merv Porter [SBS MVP]
===================================
"Javier Gomez" <javier_gomez@remove.this.bit.engineer.com> wrote in message
news:u3sASm9rDHA.2364@TK2MSFTNGP09.phx.gbl...
> Thanks for the link... Merv!!!
>
> However, on the article says: "If no valid name is found to match the IP
> address, the server blocks that message". But, how one defines a "valid
> name"? I guess... this could be different from one spam filter to another.
>
> In any event, if you come across something that explains what exactly is
> checked... let me know (I would be very interesed in learning about it).
>
> --
> -Javier
>
> << SBS ROCKS !!! >>
>
> "Merv Porter [SBS-MVP]" <mwport@hotmail.com_no_spam> wrote in message
> news:eqq8fx7rDHA.1088@tk2msftngp13.phx.gbl...
> > BTW, the link I mentioned leads to Chad's article. :-)
> >
> > --
> > Merv Porter [SBS MVP]
> > ===================================
> > "Javier Gomez" <javier_gomez@remove.this.bit.engineer.com> wrote in
> message
> > news:#9Uo2M6rDHA.684@TK2MSFTNGP09.phx.gbl...
> > > Hi Merv,
> > >
> > > I was "talking" about this with Chad on the SBS2k3 group yesterday...
> > >
> >
>
http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&oe=UTF-8&selm=ut14%23NnrDHA.1184%40TK2MSFTNGP10.phx.gbl
> > >
> > > and he pointed me out to this article on how it works (and what is
> > > required):
> > >
http://www.dnsstuff.com/info/revdns.htm
> > > which looks great... but I don't think many businness-class ADSL/Cable
> > ISPs
> > > would do that, at least here (but I'm totally guessing).
> > >
> > > Now... like I said in the that post I'm not sure how this stuff really
> > > works, but according to Chad's experience one could get away with this
> > rDNS
> > > lookup thing (even with a dynamic IP) if you change the Exchange
server
> > name
> > > to match the rDNS name.
> > >
> > > I think the bottomline is that if you have a static IP and your ISP is
> > > willing to do it... then: why not? I have good experiences using
> > SmartHosts
> > > and I feel confortable using them... so I don't worry about that too
> much.
> > > The day I get a client where I cannot use a SmartHost, then I will
start
> > > worrying about it :-)
> > >
> > > What do you think? Any idea on how exactly rDNS works for spam
> filtering?
> > >
> > > --
> > > -Javier
> > >
> > > << SBS ROCKS !!! >>
> > >
> > > "Merv Porter [SBS-MVP]" <mwport@hotmail.com_no_spam> wrote in message
> > > news:etoXRy5rDHA.536@tk2msftngp13.phx.gbl...
> > > > Hi Javier:
> > > >
> > > > Question... For those with Static Public IPs, what about having the
> ISP
> > > > create a PTR record for reverse DNS lookup? Any
> > advantages/disadvantages
> > > to
> > > > this? Those using Dynamic IPs from their ISP wouldn't be able to
use
> > this
> > > > method though (smarthost may be the only option).
> > > >
> > > > --
> > > > Merv Porter [SBS MVP]
> > > > ===================================
> > > > "Javier Gomez" <javier_gomez@remove.this.bit.engineer.com> wrote in
> > > message
> > > > news:eGXI9e4rDHA.2432@TK2MSFTNGP10.phx.gbl...
> > > > > Are you using DNS to deliver your mail? If, so this is probably
one
> of
> > > the
> > > > > anti-spam measures of AOL (reverse DNS lookup).
> > > > >
> > > > > Switch to Smarthost (relay using your ISP SMTP server's) or create
a
> > > > > specific smarthost just for AOL (I would recommend the former).
> > > > >
> > > > > --
> > > > > -Javier
> > > > >
> > > > > << SBS ROCKS !!! >>
> > > > >
> > > > > "Weasel71" <anonymous@discussions.microsoft.com> wrote in message
> > > > > news:079f01c3af84$841f6620$3101280a@phx.gbl...
> > > > > > I am running a new SBS 2003 with Exchange 2003. All email
> > > > > > for AOL gets caught in an SMTP queue and will not be
> > > > > > delivered. Do a need an additional SMTP connector with
> > > > > > different settings?
> > > > > >
> > > > > > Please help.
> > > > > >
> > > > > > Thanks
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> >
> >
>
>