🚀 go-pugleaf

RetroBBS NetNews Server

Inspired by RockSolid Light RIP Retro Guy

Thread View: demon.ip.support.pc
3 messages
3 total messages Started by pete Sat, 11 Apr 2009 09:09
Re: Demon's punts and SMTP
#892
Author: pete
Date: Sat, 11 Apr 2009 09:09
35 lines
2346 bytes
It's been a bit quiet of late in here, but I'm hoping that 
Malcolm Muir and/or Richard Clayton might still be monitoring the 
group, out of curiosity if nothing else.

GremNOS, and to a lesser extent Demon's ka9q/net, have provided 
minimal ESMTP support for years.  Recently I have decided to 
enlarge that support (in GremNOS) for the ESMTP SIZE extension 
(rfc 1870) but find that I cannot make use of it as Demon's punts 
do not (apparently) support ESMTP for delivery; at least they do 
not advertise it with an opening EHLO.

 Sat Apr 11 08:47:54 2009 helo: "helo lon1-punt3-8.mail.demon.net"

is an example of how they announce themselves.  Inspection of the 
Received: headers seems to show that ESMTP is used as the mail 
passes through Demon's MTAs, except for the final hop from the 
punts to the user's SMTP server.  Can this be changed?

I've tried to "coax" the punts by advertising "ESMTP ready" in my 
sign on banner, but that makes no difference :(  RFC 2821 
specifically forbids using any ESMTP server extensions unless the 
client uses EHLO, so unless this can be changed I'm stuffed.

Are the punts truly incapable, or is this a config setting?

Pete

PS. One additional thing I've noticed is that if I reject mail 
with a "552 Message exceeds fixed maximum message size" after the 
DATA command, this message is not apparently relayed back to the 
sender in the DSN.  Are the punts anaware of a 552 error?

-- 
   "We have not inherited the earth from our ancestors,
    we have borrowed it from our descendants."
Re: Demon's punts and SMTP
#893
Author: Richard Clayton
Date: Sat, 11 Apr 2009 16:03
33 lines
2259 bytes
In article <1239440946snz@nospam.demon.co.uk>, pete@nospam.demon.co.uk
writes

>Inspection of the 
>Received: headers seems to show that ESMTP is used as the mail 
>passes through Demon's MTAs, except for the final hop from the 
>punts to the user's SMTP server.  Can this be changed?

This is a matter for demon.service ... pretty unlikely to be an
engineering priority I'd have said -- especially since almost everyone
now uses POP3 (where you do size control another way)

but what do I know ?  see .sig

>I've tried to "coax" the punts by advertising "ESMTP ready" in my 
>sign on banner, 

that's clearly a good idea in general, but of course it won't change the
SMTP delivery code (which won't have any logic for honouring size limits
anyway)

>PS. One additional thing I've noticed is that if I reject mail 
>with a "552 Message exceeds fixed maximum message size" after the 
>DATA command, this message is not apparently relayed back to the 
>sender in the DSN.  Are the punts anaware of a 552 error?

are you saying that there isn't a DSN, or that the message attached to
the 5xx is not relayed ?

-- 
richard                       writing to inform and not as company policy

"Assembly of Japanese bicycle require great peace of mind" quoted in ZAMM
Re: Demon's punts and SMTP
#894
Author: pete
Date: Sat, 11 Apr 2009 17:21
75 lines
3845 bytes
In article  <ZNalVhBm9L4JFA9D@highwayman.com>
           richard@highwayman.com "Richard Clayton" writes:

> In article <1239440946snz@nospam.demon.co.uk>, pete@nospam.demon.co.uk
> writes
> 
> >Inspection of the 
> >Received: headers seems to show that ESMTP is used as the mail 
> >passes through Demon's MTAs, except for the final hop from the 
> >punts to the user's SMTP server.  Can this be changed?
> 
> This is a matter for demon.service ... 

I did consider that, but thought I'd try first in the group where 
those most affected (as you say below) would be most likely to be 
interested.  Follow-ups duly set.

[For those in d.s reading for the first time, this was about the 
punts initiating SMTP mail transfer with "HELO" rather than the 
usual "EHLO" signifying ESMTP.]

>       pretty unlikely to be an
> engineering priority I'd have said -- especially since almost everyone
> now uses POP3 (where you do size control another way)
> 
> but what do I know ?  see .sig

Richard, you know _everything_ ;-)  But I accept your point about 
priority, hence my query in the article as to whether this was a 
simple config issue or that the punts are physically incapable of 
ESMTP.  I would hazard a guess that the software they are running 
has not changed much over the years...

> >I've tried to "coax" the punts by advertising "ESMTP ready" in my 
> >sign on banner, 
> 
> that's clearly a good idea in general, but of course it won't change the
> SMTP delivery code (which won't have any logic for honouring size limits
> anyway)

That sounds like they are not ESMTP-capable :(

> >PS. One additional thing I've noticed is that if I reject mail 
> >with a "552 Message exceeds fixed maximum message size" after the 
> >DATA command, this message is not apparently relayed back to the 
> >sender in the DSN.  Are the punts anaware of a 552 error?
> 
> are you saying that there isn't a DSN, or that the message attached to
> the 5xx is not relayed ?

The latter.  The delivery failure was reported, but the transcript 
went something like

    A message you sent could not be delivered to the following recipients:
         pete@xxxxxx.demon.co.uk
    
    MAIL FROM:<pete@xxxxxx.co.uk>
    250 <pete@xxxxxx.co.uk> OK
    RCPT TO:<pete@xxxxxx.demon.co.uk>
    250 <pete@xxxxxx.demon.co.uk> OK
    DATA
    354 Enter mail, end with .
    
and it stopped there.  As dictated by rfc1870 and 2821, my smtp 
server waited for the closing CRLF.CRLF before sending the 552 
result code, but for whatever reason this message did not make it 
back to the sender.  Whether this is the fault of the punts or 
A&A's MTAs or Thunderbird I don't know, but suspect the first.

Thanks for taking the time to reply,
Pete

-- 
   "We have not inherited the earth from our ancestors,
    we have borrowed it from our descendants."
Thread Navigation

This is a paginated view of messages in the thread with full content displayed inline.

Messages are displayed in chronological order, with the original post highlighted in green.

Use pagination controls to navigate through all messages in large threads.

Back to All Threads