spf ent txt records.

Mark Andrews marka at isc.org
Mon Mar 18 23:13:38 UTC 2013

In message <201303181535.r2IFZ8gA017473 at calcite.rhyolite.com>, Vernon Schryver writes:
> } Turning off lookup for TXT record lookup for SPF would have very
> } little negative impact.  You would have some additional spoofed
> } email getting through and some additional blow back (which could
> } be eliminated by publish SPF records).
> I agree with this translation of that statement:
>   Google, Hotmail, AOL, and the other large inbox providers could
>   agree with the ESPs to ignore RFC 4408bis and switch to type 99.
>   They are already violating RFC 4408 and RFC 4408bis with DMARC
>   with far more operational significance.
> However, my bet is that Google et al will do as many others have done.
> They will care about the costs that you label "very little negative
> impact" and ignore those hypothetical TXT abuse scaling problems...not
> to mention complying with RFC 4408bis.
> Whatever is done by vanity domains and by domains that publish ~all
> or ?all without _dmarc will remain irrelevant.

It is or would have been, very little cost to publish SPF records.
The flag day was for publishers to publish SPF records by.  Once
you have clients not looking for TXT records there is a incentive
to publish SPF records.

Now we have the "fun" of deprecating SPF records.  When do we start
breaking zones that contain SPF records?  How long before we can
re-use the type code?  Deprecating SPF records rather than completing
the transition was a bad decision.

Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org

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