----- Original Message -----
From: "Meng Weng Wong" <mengwong(_at_)dumbo(_dot_)pobox(_dot_)com>
To: <spf-discuss(_at_)v2(_dot_)listbox(_dot_)com>
Sent: Wednesday, October 06, 2004 5:25 PM
Subject: Re: [spf-discuss] Extreme times call for extreme measures?
On Wed, Oct 06, 2004 at 03:09:55PM -0600, Jon Bertrand wrote:
|
| One of the measures is to block direct-MX connections from dsl, cable
| and dial-up networks. In your case, the reverse DNS entry for your
| server's IP address is "h-66-166-42-108.dnvtco56.covad.net". We block
| all connections from ".covad.net". This does not effect the normal
| Covad mail servers.
|
| So, is this a common thing? Is this idea gaining ground?
|
Yes, this is a common thing. In an age when most
direct-to-MX spam comes from broadband zombies, any PTR
hostname that contains its IP address is automatically
suspect. Being a subdomain of a known broadband provider is
confirmation.
Yeah, but I would wish if they would delay the PTR check to see if the user
is roaming and is going to login with ESMTP AUTH. If no login, then go
ahead and do whatever.
Technically, until the SMTP specs are refined, the LOGIN check approach is
more "compatible" with SMTP standards. The "immediate" reject is somewhat
against the specs.
Sincerely,
Hector Santos, CTO
Santronics Software, Inc.
http://www.santronics.com
305-431-2846 Cell
305-248-3204 Office