Re: More about the SPF RRTYPE

On Wed, 17 Aug 2011, Stuart D. Gathman wrote:

> On Tue, 16 Aug 2011, Alessandro Vesely wrote:
>
>> I like TXT for unstructured data, I don't think it's ugly.  For uniformity
>> with other protocols (DKIM, ADP, VBR, ...) we might introduce _spf.domain 
>> at
>> the same time as we deprecate type 99.  While only updated software can 
>> query
>> _spf.domain directly, careful use of redirection and wildcards may provide
>> for some advantages.
>
> I think that type 99 is a lost cause for v=spf1, but should be kept
> in reserve for v=spf3 - where it would be a MUST.

With type 99 for v=spf3, if you don't support v=spf3, you query TXT only.
Otherwise, you query SPF first (hopefully by the time v=spf3 is out DNS
servers will stop timing out for unknown RR queries), and TXT if not 
present to check for a v=spf1 policy.  There was no real motive to check
SPF (especially given the DNS server bugs) for v=spf1, but there is a motive
to check for the new version, which presumably lets you reject more
mail with enhanced features.  If too many DNS servers are still broken 
when v=spf3 comes out, then the parallel query thing could be
needed.  Otherwise, a lot of TEMPERRORs on email from domains with broken
servers could be a motive to get them fixed.

--
 	      Stuart D. Gathman <[email protected]>
     Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
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