[SpamCop-List] Re: The issue of bounce versus reject

[Kenneth Brody]

Mike Easter wrote:
> 
> Kenneth Brody wrote:
> > Having read the recent "why not allow bounces" thread, the following
> > occurred to me...
> >
> > Many ISPs (mine included) block outgoing SMTP connections, except to
> > their own server, to help cut down on spam/viruses by preventing any
> > direct-to-MX connections.  This means that they have to act as a
> > store-and-forward server, and can't simply reject e-mails at the SMTP
> > level.
> 
> Let's take that apart a little bit and /not/ say they are a store and
> forward.  Let's say what happens when you email out, if your mail
> provider is like my mail provider.
> 
> For my mail provider, my provider's server is an smtpauth, not a smtp
[...]
> > Note that my ISP has no way of knowing my "real" e-mail address, as I
> > don't have any e-mail addresses at this ISP.
> 
> I'm not clear on how your ISP doesn't know your email address.  Maybe we
> need to be more clear on what is an ISP, what is a connectivity
> provider, what is a mail provider, what is a news provider, what is a
> proxy provider etc.
[...]
> If I want to use a mail provider other than EL and connect to its smtp
> server, I can do that with my port 25, or I can do it with SSL port 465.

Okay, using your terminology, my "connectivity provider" is Optimum
Online / Cablevision.  It is they who provide me with a connection to
the rest of the 'net.  Although they provide me the option of setting
up e-mail addresses with them, it is not a requirement, and I have
chosen not to.  (I already have my own domains, hosted elsewhere, and
I currently forward my e-mails on those domains to my SpamCop account.)

Optimum Online blocks outgoing SMTP connections, so it is not possible
to talk on port 25 to anything other than "mail.optonline.net".  I'm not
sure about port 465.

Also, there is no smtpauth required to talk to mail.optonline.net, at
least not from within their own network.  (A quick check from my shell
account elsewhere shows that SMTP connections are refused from outside
their network.  Their MX entry shows a different server.)


So, they block all outgoing SMTP connections except to their own server.
You don't have to have an optonline.net e-mail address, and they don't
accept outside SMTP connections on that server, so no smtpauth is used.


In short, the only thing their SMTP server knows about you is the IP
address that their DHCP has assigned to you, and (I suppose) the MAC
address of your cablemodem.  Their setup means that they have no way
of knowing your true "from" address, and it also requires that they
cannot reject e-mail from you at the SMTP level.

-- 
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| Kenneth J. Brody        | www.hvcomputer.com |                             |
| kenbrody/at\spamcop.net | www.fptech.com     | #include <std_disclaimer.h> |
+-------------------------+--------------------+-----------------------------+
Don't e-mail me at: <mailto:ThisIsASpamTrap at gmail.com>