Re: [Exim] Relaying at ISP SMTP - ANSWERED

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Szerző: Johannes M. Posel
Dátum:  
Címzett: Paul M Foster
CC: exim-users
Tárgy: Re: [Exim] Relaying at ISP SMTP - ANSWERED
Dear Paul,

Come on, it's easy!

Going back 03:40 19.11.2001...

> 1. When you contact smtp.quillandmouse.com, you may get any of a number
> of XO mail hosts, selected presumably at random, or at least appearing
> so.


Your host name "smtp.quillandmouse.com" has 4 IPs associated[1].
They're named valiant, devonshire, goliath and glatton. Note that they
DO NOT HANDLE your imcoming mail for quillandmouse.com! [3]

When you'r telnetting to them, note that they call themselves "Relay"[4]
and enable you to AUTH, should you want ("250-AUTH=LOGIN) [4].

Looking at the MXes, that handle your incoming mail, we see that they
call themselves "MX"[5] and do NOT provide AUTH facility[5].

I'll take as granted from now that you understand that the servers you
send your mail to are DIFFERENT from the ones that catch your mail
from the net.

> 2. It is unreasonable to assume that one would be able to relay through
> only a fraction of these, and that which one you connected with-- at
> random-- would determine whether relaying would be allowed or not.


See your first question.

> 3. It is true that nothing in the SMTP dialog from the point of the
> first 220 message on has any bearing on whether relaying will be
> allowed. This according to RFC 2821 and according to the SMTP dialog for
> working and non-working examples.


Yes. One provide AUTH facility, the incoming MXes not. Before starting
to argue, I know you do not need to AUTH, because the servers
associated with smtp.quillandmouse.com have been configured to let you
through, if you have previously checked your mail[5]. This is called
SMTP-after-POP3[5].

> Paul


Best regards,
 Johannes                            mailto:jmp@its-toasted.org
-- 
Glück ist keine Station, sondern eine Art zu reisen


[1]
[jmp@stromgrade jmp]$ host smtp.quillandmouse.com
smtp.quillandmouse.com has address 207.155.248.47
smtp.quillandmouse.com has address 207.155.252.47
smtp.quillandmouse.com has address 207.155.248.12
smtp.quillandmouse.com has address 207.155.252.9
[jmp@stromgrade jmp]$

[2]
[jmp@stromgrade jmp]$ host 207.155.248.47
47.248.155.207.in-addr.arpa is an alias for 47.47/32.248.155.207.in-addr.arpa.
47.47/32.248.155.207.in-addr.arpa domain name pointer glatton.cnchost.com.
[jmp@stromgrade jmp]$ host 207.155.252.47
47.252.155.207.in-addr.arpa is an alias for 47.47/32.252.155.207.in-addr.arpa.
47.47/32.252.155.207.in-addr.arpa domain name pointer goliath.cnchost.com.
[jmp@stromgrade jmp]$ host 207.155.248.12
12.248.155.207.in-addr.arpa domain name pointer devonshire.concentric.net.
[jmp@stromgrade jmp]$ host 207.155.252.9
9.252.155.207.in-addr.arpa domain name pointer valiant.concentric.net.

[3]
[jmp@stromgrade jmp]$ host -t mx quillandmouse.com
quillandmouse.com mail is handled by 7 invincible.cnchost.com.
quillandmouse.com mail is handled by 7 inflexible.cnchost.com.
quillandmouse.com mail is handled by 8 indefatigable.cnchost.com.
quillandmouse.com mail is handled by 11 hood.cnchost.com.
[jmp@stromgrade jmp]$

[4]
[jmp@stromgrade jmp]$ telnet smtp.quillandmouse.com 25
Trying 207.155.252.47...
Connected to goliath.cnchost.com (207.155.252.47).
Escape character is '^]'.
220 goliath.cnchost.com ESMTP [ConcentricHost SMTP Relay 1.14] ready at Mon, 19 Nov 2001 07:31:08 -0500 (EST)
ehlo pp
250-goliath.cnchost.com Hello [213.68.72.66], pleased to meet you
250-8BITMIME
250-AUTH=LOGIN
250-SIZE 10485760
250-ONEX
250-XUSR
250 HELP
quit
221 goliath.cnchost.com closing connection
Connection closed by foreign host.
[jmp@stromgrade jmp]$

[5]
elfe:/home/elfe/posel [35]% telnet invincible.cnchost.com 25
Trying 207.155.248.15...
Connected to invincible.cnchost.com.
Escape character is '^]'.
220 invincible.cnchost.com ESMTP [ConcentricHost SMTP MX 1.27] ready at Mon, 19 Nov 2001 07:33:14 -0500 (EST)
ehlo pp
250-invincible.cnchost.com Hello elfe.inf.fu-berlin.de [160.45.45.51], pleased to meet you
250-8BITMIME
250-SIZE 10485760
250-ONEX
250-XUSR
250 HELP
quit
221 invincible.cnchost.com closing connection
Connection closed by foreign host.
elfe:/home/elfe/posel [36]%

[6]
elfe:/home/elfe/posel [38]% telnet smtp.quillandmouse.com 25
Trying 207.155.248.4...
Connected to smtp.quillandmouse.com.
Escape character is '^]'.
220 repulse.cnchost.com ESMTP [ConcentricHost SMTP Relay 1.14] ready at Mon, 19 Nov 2001 07:37:45 -0500 (EST)
ehlo pp
250-repulse.cnchost.com Hello elfe.inf.fu-berlin.de [160.45.45.51], pleased to meet you
250-8BITMIME
250-AUTH=LOGIN
250-SIZE 10485760
250-ONEX
250-XUSR
250 HELP
MAIL From:<paulf@???>
550 Not authenticated -- check your mail first
QUIT
221 repulse.cnchost.com closing connection
Connection closed by foreign host.
elfe:/home/elfe/posel [39]%