HELO vs EHLO

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HELO vs EHLO

Jos Chrispijn
Can you tell me why the 250 is followed by a '-' on an EHLO and with a HELO without that?

In:  EHLO 213.171.13.0
Out: 250-myservername.domain.com

In:  HELO reee6f7a87395a
Out: 250
myservername.domain.com

--Jos
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Re: HELO vs EHLO

mouss-2
Jos Chrispijn wrote:

> Can you tell me why the 250 is followed by a '-' on an EHLO and with a HELO
> without that?
>
> In:  EHLO 213.171.13.0
> Out: 250-myservername.domain.com
>
> In:  HELO reee6f7a87395a
> Out: 250 myservername.domain.com
>
> --Jos
>  

A space after the status code means this is the last line in a multine
reply. in other lines, a '-' is used instead. in short, it goes like this:

CMD foo bar blah
nnn-This is
nnn-a multi-
nnn-response
nnn line



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Re: HELO vs EHLO

Bill Cole-3
In reply to this post by Jos Chrispijn
At 2:57 PM +0200 5/18/08, Jos Chrispijn wrote:
>Can you tell me why the 250 is followed by a '-' on an EHLO and with
>a HELO without that?
>
>In:  EHLO 213.171.13.0
>Out: 250-myservername.domain.com

That is NOT the entire response, at least not if you are talking to a
working MTA.

>In:  HELO reee6f7a87395a
>Out: 250 myservername.domain.com


Read RFC821, RFC2821, and RFC1869. If you are looking at SMTP traffic
at this level, you cannot understand what it going on adequately
without reading all three of those (and understanding them.)

The short answer: HELO is the historic introduction command in SMTP
and using it tells a MTA to stick to the RFC821 definition of SMTP.
EHLO signals the MTA that the client wants to use some extension to
the RFC821 spec, and the response to EHLO is a multi-line response
listing the extensions supported by the server.


--
Bill Cole                                  
[hidden email]

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Re: HELO vs EHLO

Jos Chrispijn
In reply to this post by mouss-2
mouss wrote:
A space after the status code means this is the last line in a multine reply. in other lines, a '-' is used instead. in short, it goes like this:
A, I see... thanks!

--Jos