[Elecraft] Earthlink ISP problems

[k4wtf@enterzone.net]

On Sat, 19 Apr 2003, Denis Dimick wrote:

> I disagree,
> 
> Port 25 is used for INCOMING smtp (mail) traffic. Not out-going. 
> 
> Out-going traffic uses any port to connect to the remote servers port 25. 
> Earthstink was not blocking this traffic, they only blocked incoming 
> requests to your port 25. This does next to nothing to stop SPAM.
> 

Incoming vs outgoing depends on your point of view.  As an NSP our,
"customers" RETRIEVE their email using either POP2/POP3 on port 110 or
IMAP on port 143.  When they SEND email, they inject it to their SMTP
server on port 25.

Beyond that fact, Earthlink does indeed take steps to block outbound (as
in the customer attempting to connect to remote SMTP server) port 25
requests to SMTP servers except theirs.  And it does indeed to MUCH to
thwart SPAM.  You see, if the only SMTP servers that you can use are those
of your ISP and those servers won't relay email for domains other than
[INSERT.ISP.DOMAIN], the action causes a much more accurate SMTP header to
be generated showing [ISP's Mailserver] as the injection point for the
SPAM.


> I would bet that it had more to Earthstink re-writing the mail headers 
> then stopping SPAM..
> 
> If you really want to stop spam, go look at a product called TMDA, google 
> will find the site. Have only gotton once e-mail spam in over a year of 
> using it..

SPAM will only be stopped by modifying the bahavior of the
Spammers.  Short of that, taking away vectors of "anonymous" insertion is,
from the NSP point of view, the most responsible approach.  Filtering the
mail at the delivery point does nothing to address the fact that the
spammers are stealing transport service and causing undue server load.

Dennis, I do this for a living and have for the past decade.  I am a
member of the NSP Security community.  I interact with the security
personell at [insert ANY large network you want] on a nearly daily basis
as part of my duties.  I didn't pull this information out of thin air.  It
is valid and accurate.

Please try to understand the protocols and security countermeasures prior
to further spreading disinformation.  For whatever reason, people tend to
believe what they read and it is important that that information be
accurate.

73 de John - K4WTF
President
EnterZone, Inc