[Info-vax] SMTP anti-spam

[Bill Gunshannon]

In article <0ImdnXtknZjtEjHJnZ2dnUU7-cMAAAAA at mchsi.com>,
	"John E. Malmberg" <wb8tyw at qsl.network> writes:
> On 1/6/2015 11:39 AM, Stephen Hoffman wrote:
>> On 2015-01-06 17:31:02 +0000,   VAXman-  @SendSpamHere.ORG said:
>>
>>> Well, in the past, I never had any issues when sending email from EISNER.
>>
>> That usually means that the sending address or sending mail server was
>> whitelisted, that the sending server passed a greylisting check, or that
>> the message received enough credits from other attributes, or that the
>> receiving mail server didn't care about the DNS of the sending server.
>> Or the folks that didn't get the misclassified-as-spam message didn't
>> notice the message was missing and/or the folks retrieved the message
>> from a spam folder, of course.
> 
> Checking the EHLO/HELO against the rDNS is a political statement by a 
> small number of people, not a mainstream anti-spam check.

Read my lips.  It is not an anti-spam check at all. It is a check for
people spoofing the identity of machines they do not control.  Catching
some amount of SPAM is a side effect.  But stopping spoofing is just as
important and a responsibility of any competent server admin.

Or are we back to "good enough is good enough"?

> 
> The only mainstream anti-spam check on the rDNS, is simply that the rDNS 
> exists.  Again, stricter checks are only a political statement by a 
> small number of people.
> 
> Those political checks are not mainstream because of two major reasons:
> 
> 1. They are not effective in stopping additional spam that is not 
> already stopped by simpler checks.
> 
> 2. They are known to cause legitimate e-mail to be refused.
> 
> All Eisner or any other mail server needs for outgoing e-mail to be 
> universally accepted is an rDNS that does not have the text "dhcp", 
> "dynamic" or similar in it.
> 
> STATIC-96-252-127-67.BSTNMA.FIOS.VERIZON.NET should not cause any 
> problems, though I would hope that a more informative rDNS can be obtained.

When it come back up, try it at my address.  But let me know when you are
going to do it so I can find it in the logs.  I guess it is all about how
many sites you are willing to ignore.  Mis-configured is mis-copnfigured,
wether it works 90% of the time or not.

bill


-- 
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves
billg999 at cs.scranton.edu |  and a sheep voting on what's for dinner.
University of Scranton   |
Scranton, Pennsylvania   |         #include <std.disclaimer.h>