> Nico Williams <[email protected]> wrote:
> >
> > I think what you're objecting to is the section 4.3 and related text
> > that conflates "does not accept e-mail" with "does not send e-mail".
> Section 4.3 describes what is already done by existing implementations of
> this spec.
> Exim in its default configuration validates the domain part of email
> addresses and will reject mail if the sending domain does not exist or if
> its MX records point to nonexistent hosts. Exim also recognizes null MX
> records and suppresses the target A and AAAA lookups and treats the domain
> as invalid. However the null MX logic is just an optimization: Exim's
> validation logic would get the same result if it tried to do the A and
> AAAA lookups and found that . does not have any addresses.
> Postfix does the same if you use the reject_unknown_sender_domain option.
FWIW, the equivalent option in the Oracle MTA is called mailfromdnsverify.
> There are good reasons for rejecting mail from invalid domains, e.g.
> because you would not be able to send a delivery failure report.
Yep. I believe setting this option is fairly common.
Ned
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