Re: [exim] check_srv mx exists

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Autor: Klaus Ethgen
Fecha:  
A: Jeremy Harris
Cc: exim-users
Asunto: Re: [exim] check_srv mx exists
I go back to the list with that discussion...

Am Mi den 21. Jan 2015 um 13:17 schrieb Jeremy Harris:
> On 21/01/15 12:13, Klaus Ethgen wrote:
> > Am Mi den 21. Jan 2015 um 13:09 schrieb Jeremy Harris:
> >>>> How do they receive bounces?
> >>>
> >>> What do you mean, how do they receive bounces? Bounces are not different
> >>> on that level. They are just regular mails.
> >
> >> If they have no MX or A, where am I to send a bounce to?
> >
> > To the sender address as you do with MX.
>
> ... and this sender address has no MX, yes?


Well why should it? It can but it is not mandatory. As it is for every
other e-mail address.

I think you are a bit confused from how mails are send at all.

First there is DNS. In DNS you have usually an A record and/or an MX
record. The mail server uses is to MX or A (in this order) to find the
server to send mails to.

That is all, MX is used for.

Something completely different is a bounce or a bounce mail. A bounce is
just a normal mail with two exceptions:
1. It is created by the mailserver
2. It has no sender address. (Envelope(!), nothing else is relevant for
the server.

However, as all other mails, it has an recipient address that is the
envelope-from address of the original mail that causes that bounce.

Regards
   Klaus
- -- 
Klaus Ethgen                              http://www.ethgen.ch/
pub  4096R/4E20AF1C 2011-05-16   Klaus Ethgen <Klaus@???>
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