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Re: consensus call on pra/mailfrom deployment and versioning/scope



On Sep 8, 2004, at 9:37 AM, Andrew Newton wrote:

It is also the opinion of the co-chairs that many in the working group are willing to deploy MAIL FROM checking as specified in draft-mengwong-spf. Therefore, we ask for consideration of the following proposal:

The ABNF in -protocol 3.4.1 is (mostly from a post by Wayne)

   version     = "spf2." ver-minor "/" ver-scope *( "," ver-scope )
   ver-minor   = 1*DIGIT
   ver-scope   = "pra" / "mailfrom" / name
   name        = alpha *( alpha / digit / "-" / "_" / "." )

I agree with decoupling scope from the base record format. If we're going to modify -protocol, I suggest we further decouple the version string from the base record format. To wit:

version = "spf/" ver-major "." ver-minor "/" ver-scope *( "," ver-scope )
ver-major = 1*DIGIT
ver-minor = 1*DIGIT
ver-scope = "pra" / "mailfrom" / name
name = alpha *( alpha / digit / "-" / "_" / "." )

Doing this would help further delineate the static and variable parts of the version string. I also recommend that the RR type defined for -protocol be modified to drop the superfluous "2".

Sample applied use:

example.com. IN SPF "spf/2.0/pra,mailfrom mx a:smtp.example.com a:smtp.marketingco.com ?all"
IN SPF "spf/2.0/mta mx a:smtp.example.com -a:192.0.2.0/24 ?all"
IN TXT "spf/2.0/pra,mailfrom mx a:smtp.example.com a:smtp.marketingco.com ?all"
IN TXT "spf/2.0/mta mx a:smtp.example.com -a:192.0.2.0/24 ?all"

In future versions, perhaps:

example.com IN SPF "spf/2.1/xmlstr <spf xmlns='http://domain.com/1'><pra><m><mx/></m></pra></spf>"
example.com IN SPF "spf/2.2/xmldoc http://example.com/spf/policy.xml";
The question before the working group: assuming no technical errors with the above, is there anybody who vehemently objects with this proposal?

I see no harm in taking this opportunity to allow for future versions of Sender-ID with additional scopes and different record formats.

Tripp