Re: [Exim] Should I allow "MAILER-DAEMON@" as a sender witho…

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Autor: Dave C.
Datum:  
To: Ralf G. R. Bergs
CC: exim-users@exim.org
Betreff: Re: [Exim] Should I allow "MAILER-DAEMON@" as a sender without verification?
On Tue, 27 Aug 2002, Ralf G. R. Bergs wrote:

> On Mon, 26 Aug 2002 13:13:59 -0400 (EDT), Dave C. wrote:
>
> >> >>   sender verify fail for <MAILER-DAEMON@???>:
> response
> >> to
> >> >>     "RCPT TO:<MAILER-DAEMON@???>" from fw-btv-
> >> rz.bayernoil.de
> >> >>     [62.153.86.59] was 550 Mailbox unavailable: This site may not be
> used
> >> as a
> >> >>     relay agent.

> >> >>
> >> >> Should I always accept senders of MAILER-DAEMON@ without verifying that
> >> they
> >> >> really exist, or can one say that the sender's MX is broken if it
> doesn't
> >> accept
> >> >> mail to MAILER-DAEMON@ and thus I should NOT change my Exim
> configuration?
> [...]
> >> Do I understand you correctly that you are suggesting I ALWAYS accept
> messages
> >> from MAILER-DAEMON@anydomain without verification?
> >
> >Not messages with an _envelope_ sender of MAILER-DAEMON@... But you
> >should'nt reject a message merely becuase its headers contain
> >MAILER-DAEMON@...
>
> Of course I wouldn't do such a thing -- please see my original question above.
>
> >> >If this site wants to send mail with an envelope sender of
> >> ><MAILER-DAEMON@theirdom>, then they have to be prepared to accept a
> >> >bounce message in return to that address (where exim will properly use
> >> ><> as the env sender), if that message was underliverable at your site.
> >>
> >> And that means what in my case?
> >
> >I wouldnt do anything special. If the address doesnt veryfy ( and you
> >want to verify addresses ) then dont accept them.
>
> Ok, that's easy enough. :-)


Exactly. it comes down to what you want to do. As an envelope sender,
"MAILER-DAEMON" means nothing special. It is commonly used for the
header sender of bounce messages by some MTA's (but not all), but I dont
beleive there is any specification for that.

> >Its really up to you..
>
> Sure, but I'd like to Do The Right Thing(TM), and I wasn't sure what to do in
> these "esoteric" cases. :-)


If you "Right Thing" you mean "per RFC", then unfortunately you're in
uncharted territory, as I dont beleive an RFC has been written regarding
accepting or rejecting mail based on SMTP callbacks. In fact, I'm not
even sure there is an RFC mentioning callbacks at all.


> Thanks,
>
> Ralf
>
>
> --
> Sign the EU petition against SPAM:          L I N U X       .~.
> http://www.politik-digital.de/spam/        The  Choice      /V\
>                                             of a  GNU      /( )\
>                                            Generation      ^^-^^

>
>
>