Re: smtp authentication (sendmail relay)

[Lloyd Zusman <ljz@asfast.com>]

Harry Putnam <reader@newsguy.com> writes:

> Stainless Steel Rat <ratinox@peorth.gweep.net> writes:
> 
> > * Harry Putnam <reader@newsguy.com>  on Sun, 17 Dec 2000
> > | In fact, not really sure where those smtp negotiations get handled.
> > 
> > If newsguy is doing what I suspect they are doing, they don't.
> > Authenticated SMTP hooks into POP authentication.  When you authenticate
> > yourself to the POP server, a flag is set that allows you to use that
> > host's SMTP server to relay mail.  That flag is cleared after some set
> > period.
> > 
> > It is probably a bit more complex than this, but this is what the end users
> > see.
> 
> So, if that is the case then I should be able to relaty through them
> since that is my source of POP3.   So does the relay have to happen in
> conjunction with a POP3 retrieval .... Any one know how that is setup?

Well, I'm not sure if relay works via newsguy's SMTP server or not,
since I only used it to send mail to a newsguy email address that I
have.

> Maybe the messages from a staight on attempt to relay will provide a
> clue.

Yep.  I agree.  Enclosed at the bottom of this email is another
typescript showing the following scenario:

(1)  Connect to `smtp.newsguy.com' via telnet for an SMTP session, and
     attempt to relay ... this fails.

(2)  Connect to `pop.newsguy.com' via telnet for a POP3 session, and
     then immediately log out.

(3)  Re-connect to `smtp.newsgiy.com' via telnet for an SMTP session,
     and re-attempt the same relay ... this time, it succeeds.

> Couldn't think of a way to get more verbose stuff since telnet is
> disabled:

On a Unix-like machine you can type `script' from your shell, and then
enter interactive commands, such as the telnet commands to the newsguy
servers that I issued.  When you're done, you type `exit' from your
shell, and everything that appeared on your screen since you last
typed `script' will be stored in a file called `typescript', in your
local directory.  Edit out any passwords and any control characters
from this file (especially the ^M characters), and this is an exact
log of what took place within the telnet sessions.

> [ ... ]

Here's the typescript log for what I described above:

 Script started on Sun Dec 17 16:34:01 2000
 1> telnet smtp.newsguy.com 25
 Trying 209.155.56.71...
 Connected to smtp.newsguy.com.
 Escape character is '^]'.
 220 newsguy.com ESMTP Sendmail 8.11.0/8.9.1; Sun, 17 Dec 2000 13:31:53 -0800 (PST)
 ehlo asfast.com
 250-newsguy.com Hello IDENT:root@acholado.net [216.182.19.128], pleased to meet you
 250-ENHANCEDSTATUSCODES
 250-EXPN
 250-VERB
 250-8BITMIME
 250-SIZE 2000000
 250-DSN
 250-ONEX
 250-ETRN
 250-XUSR
 250 HELP
 mail from: ljz@asfast.com
 250 2.1.0 ljz@asfast.com... Sender ok
 rcpt to: ljz@nyct.net
 550 5.7.1 ljz@nyct.net... Relaying denied - please authenicate by logging into the pop server
 quit
 221 2.0.0 newsguy.com closing connection
 Connection closed by foreign host.
 2> telnet pop.newsguy.com 110
 Trying 209.155.56.72...
 Connected to pop.newsguy.com.
 Escape character is '^]'.
 +OK QPOP (version 2.3a) at perry.pathlink.com starting.  <22701.977088806@perry.pathlink.com>
 user XXXXXXXXXX
 +OK Password required for elhipo.
 pass YYYYYYYYYY
 +OK elhipo has 8 messages (11553 octets).
 quit
 +OK Pop server at perry.pathlink.com signing off.
 Connection closed by foreign host.
 3> telnet smtp.newsguy.com 25
 Trying 209.155.56.71...
 Connected to smtp.newsguy.com.
 Escape character is '^]'.
 220 newsguy.com ESMTP Sendmail 8.11.0/8.9.1; Sun, 17 Dec 2000 13:33:58 -0800 (PST)
 ehlo asfast.com
 250-newsguy.com Hello IDENT:root@acholado.net [216.182.19.128], pleased to meet you
 250-ENHANCEDSTATUSCODES
 250-EXPN
 250-VERB
 250-8BITMIME
 250-SIZE 2000000
 250-DSN
 250-ONEX
 250-ETRN
 250-XUSR
 250 HELP
 mail from: ljz@asfast.com
 250 2.1.0 ljz@asfast.com... Sender ok
 rcpt to: ljz@tiac.net
 250 2.1.5 ljz@tiac.net... Recipient ok
 data
 354 Enter mail, end with "." on a line by itself
 Subject: This is a test of newsguy relay after a pop access
 
 It looks like the test succeeded
 
 .
 250 2.0.0 eBHLYBM22848 Message accepted for delivery
 quit
 221 2.0.0 newsguy.com closing connection
 Connection closed by foreign host.
 4> exit
 
 Script done on Sun Dec 17 16:37:05 2000


-- 
 Lloyd Zusman
 ljz@asfast.com