Mailinglist Archive: opensuse (3337 mails)

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RE: [SLE] SMTP authentication was re:[SLE] mail sending and Postfix was OT: Posting from another unsubscribed address for a subscriber?
  • From: "Greg Wallace" <gregwallace@xxxxxxxxxxx>
  • Date: Thu, 27 Apr 2006 14:49:13 -0500
  • Message-id: <!&!AAAAAAAAAAAYAAAAAAAAABYv/fsiAbFHuuseWu7lbHnCgAAAEAAAALEY6wb5SOpPnxkH6JRvaKEBAAAAAA==@xxxxxxxxxxx>
On Thursday, April 27, 2006 @ 9:33 AM, Hylton Conacher wrote:

>Carlos E. R. wrote:
>>
>> The Tuesday 2006-04-25 at 12:18 +0200, Hylton Conacher (ZR1HPC) wrote:
>>
>> ...
>>
>>>>>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).
>>>>
>>>>So basically the server I enter as the Mozilla SMTP server receives the
mail
>>>>from me and sends it to the destination or next relay before the
destination,
>>>>no questions asked?
>>
>>
>> The first SMTP sever may ask questions, of course. Any SMTP server in the

>> chain, except the one of the destination address may ask for
>> authentication of some sort; ie, your ISP SMTP server may ask for it,
>> because it will _relay_ your mail to somebody else......
>OK, understood. What tyoe of authentication could a SMTP server say 3
>down the line ask for? Would its request be answered by the second SMTP
>server or would SMTP-3 try and contact the original dialup server which
>may not be currently connected?

>Time to visit an inet cafe and Google SMTP authentication methods.


>> ...........Also, if to tell
>> Mozilla to send the email you write on the gmail account through gmail
>> smtp server (bypassing your ISP smtp server), this will also request some

>> ID.
>Well when I tried sending mail using the GMail SMTP it didn't seem to
>work, although tat could have been due to user education. As it didn't
>go through I figured that it probably needed an ID on me ie I needed to
>log on first or send from my GMail account. I cannot stay connected
>whilst I read + reply to SLE mesages.

>Given that I like to/have to read my email offline is there a way to use
>teh GMail SMTP server to send email that does not originate from a GMail
>address? If someone has some info or a tutorial, I'd be most interested.

>> It would be rare that the second server asked for ID, but it could
happen:
>> for instance, in a private network users send to a certain local SMTP
>> server. This one sends to another one on their ISP, who request auth from

>> the private server (but not from the user: that is impossible).
>Right, so if I understand correctly, having my own local SMTP server
>might not alleiate the problems I am experiencing now as again the email
>FROM header is different to te dialup connection account, and they would
>have to be the same for the ISP SMTP server to accept it
OR
>As the ISP SMTP server is receiving mail from another SMTP server(my
>local one) will it not authenticate each email sent on te above criteria
>but do it another way?

>> The method used for authentication varies. An ISP can simply validate
by
>> the IP number you use. Or, it can also see that you retrieved email
from
>> them, say, three minutes ago from this IP (POP before SMTP). Or it can
ask
>> for a login/password pair.
>Are these methods also used if the sender is a SMTP server or are
>different criteria used? ie see above just below OR.

>> In other words: SMTP servers that relay email to some other smtp server
>> should normally use some kind of authentications. Those servers of the
>> destination address will not.
>OK understood that any of the SMTP servers can request authentication,
>except the destination SMTP server.

>> Another clarification: The minimum is two smtp servers in the chain. One
>> gets the email from you, the other one receives it for the addressee.
>> Depending on the setup, there can be intermediaries on both sides. Each
>> one normally adds a "Received" header to the email, and you can read them

>> (try: it is instructive).
>mmm, I've seen email headers and understand this. What i didn't know was
>that there are normally only a maximum of 2 SMTP servers ie sender and
>receiver.

>>>>>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.
>>>>
>>>>AAAAHHHH Right, my thick headedness has cleared considerably! :)
>>>>I thought there were intermediaries as if a link to a country goes down
then
>>>>the packet would need to be routed to on another path via an
intermediary
>>>>host.
>>
>>
>> No, intermediaries happens in complex setups for reasons different that
>> distance. But there might be none at all.
OK

>>>>I thought the intermediary and destination server did authentication to
cut
>>>>back on SPAM.
>>
>> No, they do other kinds of tests, but they can not ask a login/password
>> from you, they doesn't "see" you.
>OK, so , assuming a mail has to take the long path to get to the email
>destination and therefore goes from local SMTP to ISP SMTP to
>intermediary SMTP to destination SMTP and that the intermediary SMTP
>needs authentication. However because it cannot see my local server, due
>to it having dropped its dialup connection or whatever, it does other
>tests to obtain authentication.

If you send mail to a 3rd party SMTP while logged into your local ISP, your
local ISP SMTP server doesn't even get involved. Maybe I'm misreading your
above paragraph, but it sounds like you might be thinking it does get
involved.

>>>>OK, what I have managed to so far partly confirm is that my ISP is
currently
>>>>doing authentication on email the SMTP server receives from the ISPs
users and
>>>>thus they are prohibiting me from sending email from my own domain that
is not
>>>>held/registered by them, eventhough I hold a dialup and different email
>>>>account with them.
>>
>> Right! :-)
>Can this type of authentication be got around or changed ie what other
>types could I request them to rather ask me for to authenticate?

>>>>Time to move ISP's
>>
>> There are more than one way. That's not the only possibility.
>Well given what I need and what is being offered by them, and of course
>how they manage the network, and my knowledge and all, changing ISP's is
>the next easiest choice.

>If you can see a way around the authentication the ISP is doing, I'd be
>very interested to know.

Greg Wallace



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