Mailinglist Archive: opensuse (3337 mails)

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RE: [SLE] mail sending and Postfix was OT: Posting from another unsubscribed address for a subscriber?
  • From: "Greg Wallace" <gregwallace@xxxxxxxxxxx>
  • Date: Sun, 23 Apr 2006 18:30:31 -0500
  • Message-id: <!&!AAAAAAAAAAAYAAAAAAAAABYv/fsiAbFHuuseWu7lbHnCgAAAEAAAAIG1OJypF/RCgci5DluVqDkBAAAAAA==@xxxxxxxxxxx>
>On Sunday, April 23, 2006 @ 5:40, Carlos Robinson wrote:
>The Thursday 2006-04-20 at 13:08 +0200, Hylton Conacher (ZR1HPC) wrote:

>> THANKS Carlos, my reply/understanding is in-line.

>As it should always be.

>> So in essence, provided an individual/company uses the ISP of their
>> holder(ISP-1), they can use the ISP SMTP servers. If an
>> wants to obtain a domain at another ISP(ISP-2) and dial into ISP-1 to
>> mail from the IAP2 domain, it is not 'allowed' to cut down on spam?

>It depends on what rules the smtp server you want to use as relay server
>imposes on you. They can allow you, or not. Their choice.

>> There is something I am missing however :(
>> Something about the authentication :(
>> What hapens to folk who maintain their own SMTP servers(Postfix/Sendmail
>> Are they still restricted in sending mail from another another
>> via a different ISP(ISP-1)?

>If your provider is a good one they will not impede you from using their
>smtp as a relay server for all your email regardless of the from address
>you use.

>> Let me illustrate with an example on how I understand the SMTP process:
>> 1. Assume that I had a two domains registered, each with a different
>> ISP.
>> ISP-1
>> ISP-2
>> 2. I have a single Postfix SMTP server for both domains, but I cannot
>> afford to keep it online 24/7 and so I have a dialup account with
>> ISP-1.
>> 3. On first dialup to ISP-1 my SMTP server authenticates and retrieves
>> its dynamic IP from ISP-1.

>Nonononono. You get your IP much earlier that that, via ppp negotiation
>when the modem connects.

>> It first sends the outgoing email from
>> both domains to the next closest SMTP server(ISP-1's SMTP server) and
>> then receives email from POP mail stores at each domain. My SMTP
>> server then disconects itself from ISP-1.

>It sends email to the server you have told it to send to. Distance or
>ownership has nothing to do. Nor has the smtp server got to connect or
>disconect after or before you receive mail from the pop server(s).

>> 4. The mail received by ISP-1's SMTP server is marked as certified as
>> ISP-1 was able to confirm that the sender was someone who they knew
>> and who had dialed into the ISP-1 network. The message details from
>> the message sender do not matter as they came from an authenticated
>> source. If there is a problem with one of the messages sent then
>> ISP-1 will be able to identify me as the sender and I could face
>> legal action.

>I'm sorry, but I do not understand a word of what you are saying. Please,
>study the subject in manuals and howtos available in the distro, then
>explain again.

>I already explained what you needed to know, but what you say doesn't make
>any sense. Or I'm thick headed today, sorry.

>Let me try again... when you send email by any method using any relay
>server you hired, because it belongs to your isp, that email can be traced
>back to you regardless of your from address, and regardless of the method
>you used to authenticate yourself to the isp or smtp server - provided
>everything is correctly configured at their end.
>This relay server will normally send all that email direct to the
>destination address, no intermediaries. The destination server can not do
>authentification, because the email is for him: he can not reject it,
>unless he thinks it is spam or virus or such.

>- --
> Carlos Robinson

The key here is that it's the SMTP server that you use that imposes the
restriction. You can use any SMTP server that you have subscribed to
without having any problem with your ISP. I am using a 3rd party Mail
product and am not using my ISP's SMTP server. This should always be
allowed. Now if I were to log into a different ISP and try to use my ISP's
SMTP server, they might reject my mail. It depends on the policy of that
ISP. I used to live in Alaska and had 2 ISP's at one point. One of them
let me use it's SMTP server from the other, but not vice versa. I. e., one
of the ISP's had a more restrictive policy. Maybe you understood this
already, but I got the feeling maybe you didn't.

Greg Wallace

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