Re: [EXIM] bug in exim when talking to non-ESMTP host?

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Author: Paul Mansfield
Date:  
To: Exim users mailing list
Subject: Re: [EXIM] bug in exim when talking to non-ESMTP host?

Oh dear, I'm getting into an RFC debate. Looks like the problem won't go away.

The customer who is running "David Postman" (some sort Novell mail gateway,
http://www.tobit.bit) talked to their tech support at Tobit UK, and they say
that Exim is WRONG to batch mail down the same socket when the receiver can't
handle it and quotes the RFC s4.5.1:

  >      4.5.1.  MINIMUM IMPLEMENTATION
  >          In order to make SMTP workable, the following minimum
  >          implementation is required for all receivers:
  >             COMMANDS -- HELO                        MAIL
  >                         RCPT                        DATA
  >                         RSET                        NOOP
  > As you can see from this quote the SEDN, SOML, SAML are not a part of the
  > minimum requirements.


They go on to say that their system is thus a minimal RFC821 compliant box in
that it does handle the minimum... but when Exim tries multiple mails they
reply with 500, but Exim ignores it:

> The Exim-Postman system should act as follows (E: - Exim, P: - Postman):
>
  > E:   HELO   ;Establish communication
  > P:   250    ;Requested mail action okay; completed
  > E:   SEND
  > P:   500    ;Syntax error, command unrecognized
  > E:   SOML
  > P:   500    ;Syntax error, command unrecognized
  > E:   SAML
  > P:   500    ;Syntax error, command unrecognized
  > E:   MAIL   ;Minimum requirement command - recognised
  > P:   250    ;Requested mail action okay; completed
  > E:   RCPT   ;Recipient details & path e-mail has travelled (basically the

e-mail header)
  > P:   250
  > E:   DATA   ;E-mail contents...
  > P:   354    ;Start mail input; end with <CRLF>.<CRLF>

>
> ... and then the data... (Parameters to the commands are not shown.)
>
> The order of the SEND, SOML and SAML commands could be in any order - or

not used at all. The
> main point is
> that the reply to these three commands will always, under the current

implementation of
> Postman, be 500.
>
> Regards,
>
> Technical Support
> Tobit Software Ltd.


Maybe Tobit's software is really  primitive, but if they're technically
right, does Exim need to have an extremely dumb mode of operation. I find this
statement from the web site hard to believe if indeed so many ISPs use Exim and
there's so many installations of 'David' out there:
     Today more than 84,000 companies and over 2.25
     million people use our messaging software. In fact,
     you're using our information server, David 5.11, right
     now. 


and the last sentence on their http://www.uk.tobit.com/ is quite ironic in a
way:
    Network Computing magazine has this month given David their highest
    'Editor's Choice' award.  "David offers astonishing messaging
    functionalilty in a truly all-in-one solution. David is a truly
    all-purpose communication product and it is hard to think of something
    that it cannot do."



Hmmmm, ful RFC821 compliance springs to mind.

Paul


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