Re: [exim] check_srv mx exists

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Author: John Schmerold
Date:  
To: exim-users@exim.org >> exim users
Subject: Re: [exim] check_srv mx exists
Hmm, is all this to say what I have in mind cannot be done within Exim?

On Wed, Jan 21, 2015 at 6:31 AM, Ted Cooper <eximX1312y@???> wrote:

> As Klaus said, it is perfectly valid for any domain to not have MX
> records - instead it relies on the A fallback for email deliveries.
>
> Many versions of Exchange will also try the A fallback, regardless of
> the existence of MX RR, when all specified MX servers defer. This should
> be considered a bug, but it must also be compensated for.
>
> In the RFCs the A fallback is called "an implicit MX RR, with preference
> of 0, pointing to that host." (RFC 5321)
>
> When the MX RR would just be duplication of the A RR, some admins don't
> see the need to add MX explicitly.
>
> On 21/01/15 22:13, John Schmerold wrote:
> > We have had various troubles with sender verify, however I am not sure
> that
> > any of my users would care to receive messages from a domain without some
> > basic means of receiving a reply. At this point, I am not considering
> > whether the mx record is valid, but I would like to block domains without
> > one. The RBLs are strugling to keep up with all the random "innovative"
> > domains, this seems to be a good tool in the anti-spam arsenal.
> >
> >
> > On Wed, Jan 21, 2015 at 5:30 AM, Jeremy Harris <jgh@???> wrote:
> >
> >> On 21/01/15 11:18, Klaus Ethgen wrote:
> >>> There are many legit senders without MX
> >>> record. That is fully ok and there are mail admins out there that do
> not
> >>> see any reason why to add A and MX with the same content.
> >>
> >> How do they receive bounces?
> >> --
> >> Jeremy
> >>
> >>
> >> --
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> >>
>
>
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